We are excited to share our learnings and experiences to help the next generation of tech start-up entrepreneurs and blockchain developers!

• April Offers: April’s offers and promotions have launched to help STACK members pack up + go on an adventure! Members can save money and plan their trips with Contiki, Bentley, Lyft, Esso and Shoppers Drug Mart offers while Purdy’s, Dessy and AUXE provides discounts for seasonal moments in the month. More details in the STACK app!

• IN-HXOUSE Conversations Panel: STK attended IN-HXOUSE Conversations powered by Microsoft with panelists Bella Hadid, La La Anthony, Jennifer Rubio and Morgan DeBaun, moderated by Olivia Perez. The panel discussed what it means to be an entrepreneur in 2019, providing their unique perspectives based on personal & professional experience from different industries.
• STK teaches Blockchain at George Brown: Our lead developer Thomas is teaching full stack development for the Blockchain Development Program at George Brown College.

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: April 12th, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

The steps outlined in our first tutorial, are the first steps you would take before being able to use your tokens in real life.

P2P: Send + Request Money Fee-Free

The P2P feature can be used in any situation that requires you to send or receive money from another STK Mobile Wallet user. The feature is quick, easy to use and best of all, fee-free. Whether you borrowed money from a friend or want to avoid the awkward conversation of requesting money from them, use P2P.

Here’s how you will be able to use P2P.

1. Log into the STK Mobile Wallet.

2. Select Send/Request Money.

3. Select send + input amount to send or request.

4. Input your friend’s info or find them in your address book.

5. Confirm balance, input your message and slide to send.

That’s it! It’s that simple.

We’re excited to be able to provide features like P2P in the STK Mobile Wallet once it’s open to the public. STACK features will also be available on the STK app, allowing users to bring their crypto into real life beyond POS transactions.

STK Mobile Wallet: P2P Tutorial was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

The Business Development team is expecting to see exciting developments in partnerships in the coming months, stay tuned!

• CPPO Board Member: STACK has been welcomed to the Canadian Prepaid Payments Organization (CPPO) as a board member. “The prepaid industry is continuing to grow and evolve, driving new market opportunities globally. Powering this growth is the flexibility of the platform that allows for innovation to be quickly delivered to consumers who are actively looking for solutions and tools to help manage and control their financial futures. I’m proud to be joining the CPPO as their latest board member to help drive innovation and consumer adoption.”- Miro
• McMaster Nomination: Congratulations to Teddy and Nahim from the STACK team for receiving Supervisor Recognition from McMaster Engineering-nominated by former Blockchain Developer, Nat Chin.

• AUXE Partnership: STACK has partnered with AUXE, a startup serving the GTHA and London to get users $25 off their first repair. Access a mobile team of certified technicians that will diagnose and repair Samsung or Apple devices through STACK. More details in app.

• Partnerships: The Business Development team has been working on exciting partnerships for the upcoming months. Excited to share more news soon!
• AMA: A big thank you to everyone who joined our last AMA yesterday! If you missed it, get caught up on the conversation here. We greatly appreciate the support, feedback and engagement we’ve received from all our AMA’s.
• Monthly Top 10 FAQ’s: Moving forward we will be posting the community’s top 10 questions on Reddit. Telegram admins will open up time for questions the week prior to being posted on Reddit, tag your questions with #Top10FAQ.

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: March 29th, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

Got plans this weekend? STACK has partnered with Lyft to get STACK members a special offer on their rides to and from St. Paddy’s celebrations this weekend!

Bill Split is now available on the STACK app. Split any bill with your STACK friends in a few quick steps, no more awkward pay back conversations.

STACK Updates

• Bill Split: This exciting feature is now available on the STACK app. Split any bill with your STACK friends easily.

• Lyft Partnership: Kick off your celebrations by riding responsibly to and from St. Paddy’s Day parties. Lyft is offering new Lyft riders $10 off the first two rides. Available for GTHA, activate in STACK to get started.

Community:

• Women in Tech — Celebrating International Women’s Day #BalanceforBetter: In this instalment of our Women in Tech series, explores the theme of #BalanceForBetter and highlights women, projects and organizations led by women that are making the world a better place.
• ETH UofT: Our lead blockchain developer “Thomas” did a talk with former STK blockchain developer “Natalie” on Introduction to building Ethereum Smart Contracts with Solidity. Thank you to UofT Blockchain Group for organizing this awesome event, we met so many students that were excited in learning how to build dApp.

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: March 15th, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

By empowering women through technical education it can help bridge the gender gap and open up opportunities for more women in tech. Some organizations that work to nurture women’s tech talent are Girls Who Code (USA), Black Girls Code (USA & South Africa) and Kizcode (UK).

Girls Who Code, founded by Reshma Saujani, has made the gender gap and tech education more visible by recruiting high profile ambassadors — most notably Supermodel Karlie Kloss to raise awareness. Girls Who Code has reached almost 90,000 girls and aims to contribute to gender parity by 2027.

Kimberly Bryant set out to create Black Girls Code to prove that girls of every colour can code. Through workshops and after school programs, Black Girls Code provides underprivileged girls in underrepresented communities the opportunity to learn and master their technical skills. Their goal is to train 1 million girls by 2040.

Müjde Esin created Kizcode to open doors for Turkish and Kurdish speaking women in the UK who faced domestic violence and forced marriages in their patriarchal societies. It is difficult for these women to integrate into UK society because they face language difficulties and unemployment. Kizcode aims to equip these women with skills to improve their quality of life through education and nurturing their skills. By empowering these women with code, tech and computer skills, it provides them with an opportunity for a career, to reach their goals or simply sell their handmade products and recipes online as a means of income.

You don’t have to set up a coding organization to make a difference. Two women that are fighting for diversity and balance in the workplace for women are Laura Gómez and Laura Weidman Powers. Through the people analytics tool, Atipica, Laura Gómez helps companies use data to strategize hiring and build more diverse workforces. Laura Weidman Powers, who served as a Senior Policy Advisor to the Chief Technology Officer in the Obama White House, is an advocate for young Black and Latino Engineers, and works to ensure that they’re proportionally represented in the field.

When empowered with knowledge and mentored, girls and women can make the world a better place.

A group of girls from San Fernando High School in Los Angeles teamed up with DIY Girls, an organization supporting girls in STEM, to create lightweight and portable solar powered tents for the homeless. Homelessness was close to their hearts as Daniela Orozco, one member of the group who then was a senior of San Fernando, came from a low income family. Within only four years, the girls saw the increase of homelessness in their community and wanted to create a solution. Their solar powered tents has the potential to help many different people worldwide, including refugees or victims of natural disasters.

Thato Kgatlhanye from South Africa launched her company, Rethaka Trading, when she was only 18 years old. Disadvantaged children face many challenges such as lack of school supplies like school bags and being exposing to the risk of getting hit by cars while walking on unsafe roads on the way to school. Rethaka repurposes schoolbags filled with retro-reflective materials to increase visibility for the children’s walk to and from school. These bags are fitted with a solar panel that charges as the child is walking to school and when they get back home, they can use it as a light to study. “We are offering dignity, safety and access to light.” — Kgatlhanye

Although young, these women have shown great contribution to our society, much like blockchain. Blockchain technology is still maturing, but we’ve seen the impact it has already made on the world. If it wasn’t for the development of blockchain, STK Token and other cryptocurrencies, exchanges and wallets wouldn’t exist. It’s also opened up a new type of job for women in tech, Blockchain Developers.

STK’s former Blockchain Developer, Natalie Chin, who is still in school at McMaster University for Computer Science, is already making an impact in the space. Chin has been very actively involved in the blockchain community; volunteering, organizing, mentoring, and speaking at hackathons — including DeltaHacks and STACKATHON to name a few. Her talent has taken her to ETH San Francisco, where the STK team & friends won the top 3 prizes. Chin continues to work in tech in Toronto, and as a Blockchain Professor at George Brown College, where she shares her knowledge and experience to guide the next generation of Blockchain Developers.

In all these examples, we can see that when women are empowered, supported and represented in tech, they accomplish incredible things. This is one of the reasons to strive for #BalanceForBetter.

Is there a woman in tech that inspires you? Do you know someone we should profile? Leave your comments below!

Women In Tech: Celebrating International Women’s Day 2019 #BalanceForBetter was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

This past week, Miro was also a panelist at the 13th Annual Payments Compliance & Innovation Forum held in Yorkville, a neighbourhood in Toronto. STK will also be mentoring at ethUofT, next week! More details on our update below.

STACK Updates

• STACK has launched Fitbit Pay and is giving away two Fitbit smartwatches to a STACK member and their fitness buddy to celebrate! Enter through STACK’s Instagram page and visit here for full details.
• New March offers have arrived in STACK to help get members refreshed this Spring, more to come the rest of the weeks.

Community:

• Payments Compliance & Innovation Forum: Miro was a panelist at the 13th Annual Payments Compliance & Innovation Forum in Yorkville, Toronto. Mobile is rapidly changing the Payments Ecosystem in Canada, changing how Canadians do business. The panel discussed the changing view of open-loop prepaid cards and moving into the “bank account” mindset.
• The Silent Contributors of Millennial Culture Part 2 of 2: In the second part of Silent Contributors of Millennial Culture, we spotlight another four women whose technical work has help shape the way we use computers, find information online, design of modern applications and eco-friendly products in the market. It’s truly incredible how their work has built the foundations for today’s tech world.
• ETH UofT: The STK team will be mentoring Ethereum enthusiasts and students on how to develop dApp at ethUofT at University of Toronto, next week from March 8–10, 2019.
• The team continues its conversations with regulators in multiple regions and continues to take in beta feedback and improve the solution.
• A big thank you to everyone who joined our AMA yesterday, always great to hear feedback and suggestions from our community. If you missed it, you can catch up here.

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: March 1st, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

Part 2 of 2

We’re picking up on the first part of ‘The Silent Contributors of Millennial Culture’ by spotlighting another four women whose technical work has contributed to the culture we know today.

Personal Computers: Mary Allen Wilkes

Imagine having to go to a library or internet cafe every time you have to use a computer. Without personal computers, where would we be? The internet, tech industries and jobs where people could work from home or remotely would not exist. Would online shopping exist or be where it is today? Imagine processing your banking transactions, inputting personal information, or trading your cryptocurrencies on a public computer. The lack of security in processing these transactions with sensitive information on a public computer is cringe-worthy to anyone. If it wasn’t for Mary Allen Wilkes, this could’ve been our reality.

Mary Allen Wilkes is best known for her design of the interactive operating system LAP6 for the LINC (Laboratory INstrument Computer), one of the earliest systems for the personal computer.¹ Not only was she the first person to create the ‘personal computer’, she was the first person to have and use a personal computer in her home.² Although computer programming was male-dominant at the time, she decided to pursue the a career in the field because it was open to women and on a dare from her geography teacher. After graduating Wellesley College, she worked at MIT’s Lincoln Laboratory from 1959 to 1963.²

The struggles that Wilkes faced were mainly technical, because she had no prior training in coding — like many others in computing at the time.⁴ Although she quickly became a programming whiz, her codes often didn’t produce the result she wanted. Her background in psychology and experience symbolic logic which involves creating arguments and inferences by stringing together and/or statements in ways that resembles coding helped her career. In 1972, after leaving her mark, Wilkes left computer science and entered the Harvard University law school and went on to become an attorney in Cambridge, Massachusetts despite being discouraged by friends and colleagues to pursue law because of the challenges women faced in the field.⁵

‘Google-ing’: Karen Spärck Jones

How many times have you been stumped with a question at school or work and googled the answer? Need a new recipe? Looking for a new product? For the latest news? Don’t know something? Google it. We give a lot of credit to the search engine, but Karen Spärck Jones pioneered techniques that allow people to work with computers using ordinary words instead of equations or codes, a breakthrough that was important in the subsequent development of search engines.

Karen Spärck Jones, (August 26, 1935 – April 4, 2007) the recipient of the Ada Lovelace award in 2017, was a school teacher before going into computer science. One of her most important contributions was the concept of inverse document frequency (IDF) weighting in information retrieval, which she introduced in a 1972 paper.⁶ IDF helps score and rank a document’s importance in response to a user’s query, which is why the most relevant results are served to you in a search query. IDF is still used in most search engines today.

Although Jones was never discriminated, it took courage and tenacity to develop a leading academic career at a time when society’s expectations of women went little beyond their roles as wives and mothers. Throughout her career, Jones often campaigned for more women to join the computing field.

Hybrid Car Batteries: Annie Easley

Millennials are creating a demand for sustainable products, including electric and hybrid vehicles.⁷ When surveyed by Nielsen, 73% of millennials said they’d be willing to spend a little bit more on a product if they knew it was coming from an eco-friendly brand, compared to just 66% of the general public. Without the work of Annie Easley, eco-friendly vehicles may not have existed.

Annie Easley (April 23, 1933 — June 25, 2011) was a computer scientist, mathematician, and rocket scientist. She started her career as a ‘human computer’ after reading an article about twin sisters who worked for the National Advisory Committee for Aeronautics (NACA). She was one out of four African-American employees at ‘The Lab’. Throughout her 34 year career, she contributed to a number of programs including developing and implemented code used in researching energy-conversion systems and analyzing alternative power technology-the battery technology used for early hybrid vehicles and the Centaur upper-stage rocket.⁸

Easley never set out to be a pioneer, she wanted to simply get the job done and believed in her ability. Even in the face of discrimination, she persevered. When ‘human computers’ were replaced with machines, Easley evolved with the technology, becoming a computer programmer using languages like the Formula Translating System (Fortran) and the Simple Object Access Protocol (SOAP) to support NASA’s programs. She was also known her outreach programs with NASA — informing students about NASA’s work and inspiring female and minority students to consider careers in STEM. A champion of employee morale Easley was a team player, always emphasizing her appreciation and admiration for her colleagues.

User Interface and Intuitive Design: Susan Kare

The technology we interact with has been more intuitive than ever, and this change was influenced by Millennials. Millennials are the first digitally native generation and is the largest generation in American history, therefore they have large and increasing purchase power.⁹ If a brand wants to reach a younger audience, the user interface and design of the product has to be intuitive and aesthetically pleasing.¹⁰ Apple is an influential leader of UI — users don’t feel like they’re just looking at a screen, they feel as if they’re interacting with a whole world beyond it.¹¹ Susan Kare is responsible for some of Apple’s signature graphics to this day.

Susan Kare is an American artist and graphic artist who created many interface elements and typefaces for the Apple Macintosh in the 1980’s. Kare joined Apple Computers after receiving a call from Andy Hertzfeld to design the user interface graphics and fonts. Kare developed the idea that the graphics should be easily readable symbols that correlate to real world objects. Some iconic symbols she designed were the Apple clock, the pointer finger, the trash can and the command key which was inspired by a Swedish symbol for a castle.¹² After Apple, she went on to work as a designer for NeXT, Microsoft, Facebook and Pinterest. As of 2010, she heads a digital design practice in San Francisco and sells limited-edition, signed fine-art prints.

The challenges Kare faced revolved around her work experience. At the beginning of her career at Apple, she was faking it until she made it. She had never designed a computer icon or a typeface before, so she just winged it, never imagining that her work at Apple would become so revolutionary.¹³ MoMA honoured her work by adding her original Apple sketches to their permanent collection. “Design is for everyone, and Kare’s success proves that not only is great design universal, it often happens in spite of things like credentials and direct experience.” — John Brownlee in an article for Fast Company.¹⁴

The technical contributions of these women has changed how Millennials are using computers, find information and user interface design of everything from technology, products, websites and applications. User Interface was especially important when it came to designing the STK Mobile Wallet. “The overall user experience of blockchain and cryptocurrency has been notoriously unintuitive and unfriendly for average users. The space is filled with all jargons exclusive to people who are deeply passionate in the technology. It presented us a new realm of challenges. The wallet was designed to be intuitive and easy to use regardless of whether the user is new or experienced with crypto.” — Joanna Chen, STK UX Designer.

That’s it for our ‘The Silent Contributors of Millennial Culture’ mini series for Women in Tech. The contributions of these women have not only shaped Millennial Culture but the technology that allows cryptocurrencies to exist. We’ve since been able to build on the fundamentals of what they’ve built, enabling technology and blockchain to thrive. Is there someone else that has contributed to Millennial Culture that we should spotlight? Let us know what you think in the comments below!

Resources:

1. https://en.wikipedia.org/wiki/Mary_Allen_Wilkes
2. https://mashable.com/2018/03/08/unsung-women-in-tech/#RwYYHsGZFkqB
3. https://ethw.org/Mary_Allen_Wilkes
4. https://www.nytimes.com/2019/02/13/magazine/women-coding-computer-programming.html
5. https://spectrum.ieee.org/geek-life/profiles/computer-science-a-womans-work
6. https://spectrum.ieee.org/geek-life/profiles/computer-science-a-womans-work
7. https://thenewswheel.com/millennials-are-creating-a-demand-for-sustainable-products-including-hybrid-and-electric-vehicles/
8. https://www.nasa.gov/feature/annie-easley-computer-scientist
9. https://www.forbes.com/sites/micahsolomon/2018/05/03/for-small-business-week-all-about-millennial-consumers-and-millennial-friendly-customer-experiences/#592be9862f91
10. https://www.commercialintegrator.com/audiencecontent/user-interface-design-millennials/
11. https://www.wired.com/2016/06/apple-taught-world-smartphone/
12. https://en.wikipedia.org/wiki/Susan_Kare
13. https://www.fastcompany.com/3043312/moma-recognizes-susan-kare-the-designer-of-the-macintoshs-original-icons
14. https://www.fastcompany.com/3043312/moma-recognizes-susan-kare-the-designer-of-the-macintoshs-original-icons

Women in Tech: The Silent Contributors of Millennial Culture: Part 2 of 2 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

Recent Progress:

Crypto Android V2 Development

• Continue polishing the app with feedback from beta users

STACK Updates

• New offers have launched on the STACK app! Members are still eligible for $15 off Style Plan by Frank And Oak, $15 off first order of foodora and up to $40 off on HelloFresh. Don’t forget to check the app throughout the month for surprise offers!

Community:

• ETH UofT: The STK team will be mentoring Ethereum enthusiasts and students at ethUofT on March 8–10.
• Lightning Series Part 3: In the final part of the ‘Lightning Series’ by Aleksa Jovanovic, we provide you a tutorial on running your own Lightning Node locally & from an Android phone!

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: February 15th, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

Getting Started

In the final part of our Lightning series we will be walking you through running your own Lightning node locally and from an Android phone! Once both nodes are running we will fund the wallet attached to our Android node with test Bitcoin, open a payment channel between our Lightning nodes and make some payments.

Disclaimer: unfortunately this tutorial is tailored for mac users only :(

Overview

To start off, we are going to install btcd and its dependencies and download the Bitcoin testnet blockchain. Next, we will install lnd and its dependencies. While we wait for the testnet blockchain to finish downloading we will break down and set-up the Android code responsible for the Lightning network functionality. Lastly, we will run all of our nodes, open up some payment channels and make it rain.

Toolchain

• btcd, a Go implementation of the Bitcoin protocol
• lnd, a Go implemention of the Lightning protocol
• Android Studio for compiling and running your Android code
• serveo to expose your lnd node incase the port 9735 is blocked

Installation

Installing btcd and Dependencies

Since the btcd project was made in Go, we will first need to install Go. The easiest way, by far, to install Go is via homebrew. If you dont have homebrew, then you can follow instructions here. If you have hombrew, then simply write the command $ brew install go in your terminal.

After you have installed Go make sure to export your GOPATH and add it to your PATH.

$ export GOPATH=~/gocode
$ export PATH=$PATH:$GOPATH/bin

I’ve created the directory gocode and used it as my GOPATH directory to store any dependencies installed with go. You can use the same directory name or create your own.

Next, let’s install btcd and its dependencies.

$ go get -u github.com/Masterminds/glide
$ git clone https://github.com/btcsuite/btcd $GOPATH/src/github.com/btcsuite/btcd
$ cd $GOPATH/src/github.com/btcsuite/btcd
$ glide install
$ go install . ./cmd/...

Make sure not to get confused with line 2 and 3 as it is one command. Now, let’s spin up our Bitcoin node and download the testnet blockchain.

btcd --testnet --txindex

The --txindex flag tells the Bitcoin node to maintain a full hash-based transaction index. This will greatly improve the speed of our Lightning node.

Let btcd run and download the blockchain, this should take about 4 hours. In the meantime, let’s open up a new terminal window where we can set-up lnd.

Installing lnd and Dependencies

To install lnd and all of its dependencies run the following commands.

$ go get -u github.com/golang/dep/cmd/dep
$ go get -d github.com/lightningnetwork/lnd
$ cd $GOPATH/src/github.com/lightningnetwork/lnd
$ make && make install

lnd and lncli, lnd’s command-line interface, should now be installed on your machine.

Alright, let’s create a config file for lnd so that we don’t have to provide a tome of command-line flags every time we want to start our node. By default lnd will look for its config file in $HOME/Library/Application\ Support/Lnd or you can specify an alternate location using the flag --configfile=/path/to/config. A sample config file that contains all the possible configuration options can be found here. The configuration we will be using will be much more concise and looks like this:

bitcoin.active=1
externalip=<YOUR EXTERNAL IP>
btcd.rpcpass=kek
btcd.rpcuser=kek
bitcoin.testnet=1
bitcoin.node=btcd
btcd.rpchost=localhost

Make sure the config file is named lnd.conf.

Setting-up Our Android App

You can download the Android code from our public github repo here. Most of the major lifting is done inside either MainActivity.java or App.java Let’s start by breaking down what some of the code does.

Pro tip: Press shift-shift to search the whole Android project and use cmd+click on a member or function name to find where it’s used.

This is the wallet initialization code inside MainActivity.java. Basically, using the getWallet(final File datadir) function, if a wallet doesn’t exist it generates a wallet seed file and sets the encryption password to the specified password. If one does exist, it retrieves it. Then, it initializes an Electrum wallet with the local wallet so that the Lightning node can use the Bitcoin backend provided by Electrum.

Side note: The password is set inside of the getWallet(final File datadir) function and you should probably make it something more secure than “123456”

If you want to see your wallet address so you can send test Bitcoins uncomment the following code inside the initWalletNode(App... params) function.

Handler handler = new Handler();
handler.postDelayed(new Runnable() {
    @Override
    public void run() {
        Log.d("address", app.getWalletAddress());
    }
}, 20000);

Then, inside Logcat you will see your address logged under the identifier address.

The next block of code we are going to look it is the function openChannel(String deposit).

For testing purposes, breakpoints on lines 11, 13, 16 and 25 are very useful!

It’s fairly simple so I’ll just give you a quick explanation. This function makes an asynchronous call to openChannel(final FiniteDuration timeout, final OnComplete<Object> onComplete, final NodeURI nodeURI, final Peer.OpenChannel open) inside App.java and then waits for the OnComplete<Object> to return a result.

Let’s take a quick look at openChannel inside App.java.

For testing purposes, breakpoints on lines 7, 10, 14 and 19 are very useful!

Essentially, line 19 is calling the the Scala module to open a connection with a peer and from lines 4–18 are waiting for that call to complete. If the connections fails, then an error is thrown. If it succeeds, then the Scala module is called again on line 12 to create a payment channel using the final Peer.OpenChannel open object. This object was passed from MainActivity.java and contains data such as amount of satoshis to fund the payment channel, the node uri you are opening a payment channel with and the amount of fees you are paying for the transaction.

Lastly, let’s check out how Lightning payments are made.

Initially, the expiry for the payment request is checked and the fees are set for the transaction. Then, on line 7 an asynchronous call to the Scala module is made to initiate a payment, passing in the amount to be paid, the node id derived from the uri of the node you are paying and some routing info . If the payment succeeds, then all is well, otherwise the onFailure(Throwable failure) throws Throwable method is evoked. Right now this method doesn’t do anything, but ideally you would have some sort of notification appear in the GUI.

Running

Hopefully, btcd has finished downloading the blockchain. You’ll be able to tell if it’s finished if new valid peers are connecting to your node.

Now, shutdown btcd by pressing Ctrl-c and restart it with the command btcd --testnet --txindex --rpcuser=kek --rpcpass=kek. The last two flags are the username and password lnd will use to connect to btcd. I chose kek for the fun of it, but you should probably choose something more secure 😛

Next up, let’s run lnd in a separate terminal window using the command lnd, but make sure you have set-up your lnd.conf file. Upon first start-up you will be prompted to create your first wallet, so go ahead and open up a new terminal window and type lncli create and follow the directions on screen.

Once you have created your wallet you can switch back to terminal with lnd and see some cool action taking place! Here are a few useful commands that will come in handy:

• lncli --macaroonpath <PATH TO YOUR ADMIN.MACAROON FILE> macaroons are used as a means of wallet authentication and sometimes lncli won’t be able to find the admin.macaroon file. If lncli can’t find your macaroon file then it will throw and error when you try to run anyone of its commands.The location of the macaroon file is $HOME/Library/Application\ Support/Lnd/data/chain/bitcoin/testnet/
• lncli listpeers lists peers connected to your Lightning node
• lncli getinfo gets info about your Lightning node
• lncli addinvoice -amt <AMOUNT IN SATOSHIS> generates a pay request to be paid by someone participating in a payment channel with you
• lncli connect <NODE URI> connects to a peer using their node uri
• lncli disconnect <NODE PUB_KEY> disconnects from a connected peer using their pub_key found when you use the command lncli listpeers. You’ll notice that the pub_key is just the first part of the node uri without the ip address or the port
• lncli unlock unlocks your wallet when you start-up lnd. You will be asked for the password you used when you created the wallet during the initial start-up of lnd
• lncli listchannels lists all active payment channels you currently have with other nodes
• lncli openchannel <NODE PUB_KEY> <AMOUNT IN SATOSHIS> opens a channel with a node with a specified amount committed to the channel
• lncli closechannel <FUNDING_TXID> closes the provided channel cooperatively using its funding_txid from its channel point. The channel point has the format funding_txid:output_index. If you want to close the channel unilaterally, then use the flag --force as well
• lncli pendingchannels shows you payment channels awaiting confirmations
• lncli walletbalance shows us our wallet balance

Alright, now that we have covered some of lnd’s basic commands we can move onto actually connecting our nodes.

You may have noticed that the port which lnd accepts peers on is 9735. This port is most likely closed by your firewall so we will need to use serveo in order to forward traffic to us. Run the command ssh -o ServerAliveInterval=999 -R 9735:localhost:9735 serveo.net. Essentially, this is telling serveo to forward traffic from their port 9735 to ours using the domain name serveo.net.

Make sure to put serveo.net in place of <YOUR EXTERNAL IP> in your lnd.conf file.

Now, we need to get our nodes uri by using the lncli getinfo command. The uri will be inside of the uris block and there should only be one with the format id@ip_address:9735. We will pass this uri in on the simple Android GUI provided in the github repo so that our mobile node can connect.

Let’s start up our Android app. If you have an Android phone you can plug it in now, if not then you can just run the app on a simulator. Run the app in debug mode because some of the debug logs I’ve placed throughout can be useful.

Once the app gets going you’ll be greeted with this screen:

If you remember earlier, I mentioned how you can retrieve your wallet address. Go ahead and do that and use this site to send yourself some test Bitcoins 💸 Since this little demo is pretty primitive, you can restart the app and you should see your wallet balance updated, however sometimes getting the transaction confirmed takes a little bit.

Grab your node uri from earlier and pop it into the Node URI field. If you are using an actual Android phone I suggest checking out Vysor’s free viewing software because then you’ll have a continuous clipboard from your mac to your phone and you’ll be able to use copy and paste! The minimum amount allowed for a deposit is 0.002BTC. I usually use the amount 0.00211 for the deposit amount so that it’s easily recognizable in the feed of lnd. After you have filled out the Deposit field and the Node URI field, you can smash that CONNECT button.

Sometimes you will get “could not connect” errors, if it persists try restarting your serveo ssh server, I’ve found that to help when my node is behaving unpredictably.

Behind the scenes, the Android node is connecting to your local Lightning node and opening up a payment channel simultaneously. This may take a while, but over on your lnd feed in your terminal you should be able to see the fundingRequest coming through.

You’ll know its the right one because of the unique amount of 0.00211 😄

If you lncli listpeers you should be able to see a new node connected that had the same uri as the one shown in the funding request.

Congrats! Your nodes have made contact 👽

Confirming the channel will take a little longer, but you should be able to see it in your pending channels by using the command lncli pendingchannels.

After some time, mine took 1 hr, you should be able to see your newly confirmed payment channel with lncli listchannels. Using mine as an example, from my fundingRequest we can see that my Android nodes uri is 02d1ec413020849d509826c8636efcefc3e2011bb60e51693663d5973dbb6baec2 and here is my open channel:

Bang 💥 we are almost there. Let’s get that Lightning cash flowing now. Using lncli addinvoice -amt 1000 we can generate a pay request for 1000 satoshis.

Back on the Android screen, enter the pay request into the Payment Request field. You can find the payment request in the invoice generated as the value for the pay_req key. In our case it’s lntb10u1pwp4dgdpp5mwsv6nha0jpzngjwl8nuku8xc4a18xaq68khkcz4xw0r0y94rzesdqqcqzys8sacssefge8157zjrsskrgf5d6xnhd4jd3fnyte5k0hcyguxd9rxsg2ky27y5a7xa2kfmeynw23hrppy6mw92fkvngu3zvnu422xthsqwaj96f Now, hit the SEND PAYMENT button.

Would you look at that, the payment has been received by our local node. If we check out the payment channel with lncli listpeers we see that the local_balance is now 1000 satoshis! How cool 😎

Now, let’s close up the channel and claim the funds we were sent by our Android node. Wait, first let’s check how much we have in our wallet prior to closing the channel with lncli walletbalance.

You’ll notice that this channels point differs from the channel point in the image above, unfortunately I had to restart the process and forgot to grab a new snapshot. Bare with me.

Alright, now let’s close up the channel. Notice the funding_txindex we grabbed from the channel_point.

Side note: whenever you receive a txid of any sort, you can plug it into this site to see how many confirmations you have because sometimes you’ll be waiting for an hour… Just make sure you are on the test BTC network.

Since we did a force close we will have to wait for the CheckSequenceVerify(CSV) timelock on the contract to expire and that could take up to a day or two.

If we take a look at our pendingchannels, we see our channel, under pending_force_closing_channels, with a field called blocks_till_maturity. This is how many blocks need to be confirmed in order for the timelock to expire.

Well, that was underwhelming. As you can see, we have passed the number of blocks required for maturity, but the 1000 satoshis are still in limbo.

Unfortunately, there are some issues going on right now with the lnd’s Lightning Network sweeper. These issues will probably be resolved by the time this article is released. Essentially, a sweeper is a part of the codebase that helps finalize inputs and outputs when a payment channel is closed.

I reached out to the lnd team and they said that they are currently working on this.

And thats all she wrote folks.

Hope you guys enjoyed our Lightning series and took something away from it. This last tutorial was quite dense, but for a real blockchain diehard I think some really valuable information can be gleaned from it. Thanks for reading and make sure to check out the rest of our content and stay tuned for cool things we have coming up.

Android Lightning Tutorial was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.

We had a great year and again we’d like to thank our community for all your support! With STK now on the Ethereum Mainnet, our payment solution now works on Mainnet with every ERC20 token which provides real economic value. It also allows us to onboard more users into beta. On STACK side, the app has reached over 60k installs in just 5 months! Here’s what we’ve been working on.

Recent Progress:

Crypto Android V2 Development

• User can load Mainnet STK and DAI onto the app and convert

Server

• Migrate all the endpoints to communicate with Ethereum Mainnet
• Ensure all the payment channel functionality works as expected on Mainnet

STACK Updates

If you’re a STACK member, two exciting things are kicking off in the STACK app today…

• #STACKHacks: Since the launch, STACK users have shared amazing deals, discounts and ‘hacks’ on the STACK Worldstream. Starting today, #STACKHacks will be ran monthly, winners can now enter to win $100 CAD by sharing engaging pictures of their hacks.
• New Offers for February are now available on the STACK app to treat your Bae, or yourself! Be sure to check the STACK app throughout the month for some surprise offers.

Community:

• STK Video Series: STK is rolling out a video series demoing the STK Mobile Wallet. In the first video, we teach you how to load your token into the STK wallet for instant POS transactions. The videos will showcase the features and functions of the wallet, which can be easily used by both beginners and experts in crypto.
• Women in Tech — The Silent Contributors of Millennial Culture Part 1 of 2: In continuation of the Women in Tech Series, this two part series spotlights women whose technical work has helped shape Millennial Culture. The first part of ‘The Silent Contributors of Millennial Culture’ spotlights four very special women, whose work has impacted the use of smartphones to the music that we know today.
• Lightning Network — Part 2 of 3: In part two of our ‘Lightning Network’ series, @Aleksa details some challenges we’ve encountered while working with the Lighting Network.
• A big thank you to everyone that joined into our last Reddit AMA. We always appreciate your feedback and your support! Catch you at the next one.

That’s it for now, we’ll see you in two weeks with more to report. As always, join the conversation anytime on Telegram, Twitter, Discord and Reddit. If you’re interested in partnering with STACK or STK, get in touch with us. To download the app, visit the STACK website.

STK Progress Update: February 1st, 2019 was originally published in STK Token on Medium, where people are continuing the conversation by highlighting and responding to this story.