Gotta Catch ’Em All — Apple’s iOS content blockers

This post sums up the history of a German advertising blocker between 1998 and the dot-com collapse. Later it gives a short overview over the different web filters for iOS 9 devices. In September 2015 the world changed a tiny bit as Apple unlocked the brand new type of filters on the mobile web — content blockers. Apple’s move produced nearly 151 distinguishable content blockers. Therefor the post introduces the science of adblocking software.

As a kid my very first Internet experience was inevitably on AltaVista. I remember searching for pictures of railroad cars and saving them onto the hard drive. Fortunately pictures have very little language barriers. Whatever AltaVista hyperlinked to Japanese or French wagons, as long as they looked like boxcars I was happy. Only several months later, in fall 1999, the German web took me from pictures to text.

By starting first on AltaVista-dot-com I totally missed a huge uproar on the dot-de web. At that time, webmasters engineered a full scale attack against a German adblocker named Webwasher. Webwasher was distributed by an IT service organization of the multinational company Siemens. Siemens, infamous for their washing machines “Made in Germany”, let their employees block interactive advertising left and right. Already in 1998, various missclicked banners and pop-ups were not seen for their benefits, but for their diversion from productive work. Thus the goal of the Siemens’ adblocker was to change net usability of the working force, a group that just begun being addicted to the corporate paid Internet.

Other companies started to purchase the Webwasher from Siemens, as it promised to transform an easily distracted jobholder into a fully optimized worker. An adblock administrator could for example go into the settings menu and turn off nearly all animated banners. In one such mode, Webwasher users would still be able to view GIF advertising, however it was limited to show only the very first frame — hence transforming a once vivid banner into a motionless promotion. Rigid or unclicked banners paid less, claimed and screamed the webmasters. Some of them even threatened to stop utilizing the German kitchen equipment if Siemens should not bow to their demands. The semi-automated filtering mechanism should cease, at best completely. One particular decision was seen as a horrendous sin. Siemens, as it turns out, not only sold adblockers to corporations, they also gave their advertising filters to Internet users for free. Just like nowadays the filtering and whitelisting of ads became a daily job for a growing number of net citizens.

I would prefer to write more about the struggle between the German webmasters and a big corporation, unfortunately most sources from that time are gone forever. The dot-com bubble hit the dot-de people as tough as everywhere else on the World Wide Web. Without decent primary sources, it’s hard to tell if the webmasters from 1998 and 1999 really believed that using an adblocker could violate copyright law. The mistake of not fully preserving national adblockers and discussions around such tools should not be made twice. But it could be made twice. The process of developing an iOS 9 adblocker or content blocker right now is so simple that hundreds of blockers will shove one another just to gather the attention of users.

Due to the fact how easy it is to overlook many content blockers, I searched and gathered data on every one of them. It turns out the walled garden of Apple will be populated by dozens of Internet filters. Most will have similar names and resembling features, first and foremost against display advertising. There were already twenty-five different content blockers announced at the start of iOS 9 in September 2015. As a kid I collected pixelated railroad cars on AltaVista and missed everything about adblockers, but this time I’m gotta catch ’em all!

iOS 9 content blockers and their icons

A short overview of iOS content blockers sorted by their names. The aim is to show the main differences and goals of the content blockers, thus mostly keeping silent on their basic features. Claiming that a certain filter tool can cut the Safari loading times in half on the pages of The Verge is no longer a distinguishable criterion as most content blockers can do that. Uniqueness it is. In the end only the later reviews will reveal if the described pledges are taken seriously or are just plain software marketing.

1Blocker, @1BlockerApp: The preinstalled filter lists involve the option to block adult sites, social media widgets and Disqus comments. Users can build their own filter rules with an “advanced web editor”. Individual rules like hiding certain pop-ups can than be exported and sent to the mobile device.

Ad Block Multi, Facebook: First the app makes clear that it does not work as a VPN or a proxy. Instead it tries to stop its adversaries by filtering out “malware and spyware” with a list of certain domains. The current plan of Facebook to track web citizens for advertising purposes might encourage Ad Block Multi users to turn on the “AntiFacebook” feature.

Ad-Blocker, @SFAdBlocker: The 15 and 17 years old developers from Netherlands are responsible for this hyphen content blocker. Ad-Blocker might block most sharing buttons and tracking scripts. The basic features will be free, while others like “clickbait blocking” will be sold through an in-app purchase.

Adamant, @cocoaapp: The app declares an end to “unwanted distractions” like comments on the web. Adamant wants to focus on quick support for glitched sites and pesky bugs. After a one-time in-app purchase Adamant can be automatically updated by the “Over-the-Air Updates” feature.

Adblock Fast, @adblockfast: Filtering advertising consumes energy and space on users devices. Adblock Fast wants to optimize every bit and byte that behaves like a sloth. Shrinking CPU and RAM consumption, page loading times and the number of filtering rules per page will be its goal.


AdBlocker, Facebook: The fundamental of most adblockers and content blockers are up to date and errorless filter lists. AdBlocker lets the community share the most liked filter lists. Every user will have the ability to rate the public filter lists of other members. The app was developed by Danny Smolinsky.

AdBomb: To circumvent the limit of 50.000 filter rules and to reduce overhead, the app starts with an own handcrafted set of filter lists. Openly managing the filter lists and the privacy policy, it makes a pledge for transparency. AdBomb also promises “fast customer response”.

Adios, @Adios_app: Some sites and apps on Android devices already use anti-adblocking measures. Adios might not only hinder such technical and psychological communication attempts, but also stop like buttons and malicious scripts. The setup process helps finding the fitting filters by choosing the desired country. Adios won’t be released, but the project has been made open-source to help other developers.

AdMop, @seviu: Most content blockers are aimed at western societies, which is reflected by the variety of their filter lists. AdMop adds blocking support of Chinese and Arabic ad networks. AdMop’s UI includes little icons to show those filters, some of them are pictured as contours of countries or languages.

BlockBear, @theblockbear: The in-app promotion material shows a feebly sheep that is turned into a large bear with a click of a button. BlockBear simplifies whitelisting by allowing the blocking of ad tracking without having to block ads. BlockBear’s laser-based zapping of ads is set up on community filter lists like EasyList, EasyPrivacy and AntiSocial.


Blockparty: Some understanding of software involves heavy testing. Blockparty looks like a GitHub project developed to test out the possibilities of iOS 9 content blocking. It might not see the broader light of public.

Blockr, @getblockrapp: Some content blockers only target online advertising, others look for a reduced user interface in addition. Blockr is one of them. It hunts down cookie warnings and social media buttons. Other features involve 3D Touch and the blocking of media files to lighten the data plan.

Crystal, @_CrystalApp: Quickly launching and building a closed beta has allowed the app to give beta invites to journalists securing early interviews and reviews. Before launch 11.000 potential beta testers were standing at Crystal’s door. Additionally Crystal might improve multitasking by reducing the reloading time of websites.

Freedom, @Freedom_iOS: Publishers, users and several third-parties have sealed an agreement to view ads in exchange for content we are told. Freedom seeks to liberate users that believe in such agreement for a “smooth […] and elegant” web. In return Freedom unsurprisingly promises not to show any in-app advertising or ask for a purchase.

Hide & Seek, @hidenseekapp: Being logged into Bing or Google may change search results and that puts users in additional filter bubbles. Hide & Seeks aims to stop both search engines from combining users with their search queries by blocking cookies. It’s important to note that Hide & Seek does not hide or seek ads.


Just Content, @JustTheContent: The suppression of cyber ads in Netscape and selecting readability modes in other browsers or absorbing RSS feeds are ways to get content with less ads. Just Content recommends heavily to whitelist sites as an alternative. Nonetheless, an exemplary legitimation for blocking states that “mobile networks were never designed to deliver ads” in a battery-friendly way.

Mature Content Blocker, @austintooley: The current web is full of crude distractions and it has always been so. Mature Content Blocker aims to filter the net until it’s a kid and family friendly environment. Indeed, for adblock users it is fairly usual to eliminate the comment sections and other toxic pits.

Open Adblock: The principles of building an “open” content blocker consists of the faith in open source and spreading the software at no charge. Multiple developers followed the call of Open Adblock immediately. Open Adblock is still in development mode to be able to erase analytics.

Peace: Demanding the need of further development from pop-up blockers to content blockers is challenging. For that Peace gave a trial to many public “hosts files”, however it finally decided for a corporate database. Using databases for the filters comes with a price, Peace had to pay license fees to shutup.css and Ghostery. Two days after the launch the developer shut the app down.

Purify, @purify_app: The app challenges other content blockers by comparing them in benchmarks and features like “VoiceOver support”. However Purify does not want to stop there — images, scripts and fonts could also be filtered. Blocking fonts should not come with a surprise, the newest anti-adblocking measures involves changing the fonts for adblocker users to Comic Sans.


Quick Blocker, @fiam: This app uses the imagery of a divided Safari browser, showing one side with the content blocker and the other without. Comparisons with Two-Face from the Batman universe were probably unintended. The Quick Blocker’s emphasis on speed and shrinking the page size is underlined with different benchmarks.

Refine, @RefineApp: To reduce confusion the developer changed the name from Safari Adblock to Safari Blocker and later to Refine. The filter lists will give users a bunch of customizable options like the ability to turn off CSS. Safari Blocker will show the most popular filters determined by the number of users following such lists.

Shut Up, @RickyRomero: ‘Don’t feed the trolls’ is one of the worldly wisdoms or one of the major erroneous narratives of the Internet. However, because numerous trolls and harassers live on Internet comments, especially female users want to filter them out. Shut Up also allows its users to put exceptions for their favorite non-toxic sites. The app was developed by Ricky Romero.

Silentium, @silentiumapp: The app wants to achieve “ethical content blocking on iOS 9”. The main emphasis on ethics is implemented by potentially improving the process of whitelisting sites.

Vivio, @vivioapp: Having a filter list with all sort of sites and languages can slow down even the fastest blocking software. Instead Vivio focuses on a number of designated filter bubbles on the net, storing their filters on own servers. For example it filters the web in Slovakia, Czech Republic or Germany.


Giants: Well known companies like BetaFish Incorporated (AdBlock) or Eyeo GmbH (Adblock Plus) took surprisingly long to bring their own iOS 9 content blockers into the game. The Electronic Frontier Foundation (Privacy Badger) may or may not develop an own content blocker for Safari.

Others: After one month of collecting blocker apps on the App Store several pirated blockers were seen published and afterwards banned. In total at least 151 content blockers had a way to contact the developers and a trustworthy homepage or social media presence: 17 Ad Blocker, Ad Blocker by Idan Sheetrit, Ad Blocker by Imaggle, Ad Blocker by Ravilla Thirumala, Ad Blocker by SurfEasy, Ad Blocker Free, Ad Blocker Kit, Ad Blocker Pro by Chintan Patel, Ad Clean, Ad Content Blocker, Ad Control, Ad Kill/Ad Kill Pro, Ad Shield by Dominic Rodemer, Ad Stopper, AdBlaster, AdBlock by Alexander Martynenko, AdBlock for Kids, Adblock Safari Edition, AdBlock+, AdBlocker Awesome, AdBlocker by JG Applications, AdBlocker™, AdJunk, Adpocalipse Blocker Pro, Ads Be Gone, Ads Blocker by Codefavor, Ads Blocker by Bui Duong, AdsDown, AdStop, Antelope, Anti-Porn, Ascendent, Been Choice, Blacklist Ad Blocker, Blkr, Block Advertising Pro, Block it All, Blocker by Alexander Akhmetov, Blocker by Linjun Zhang, Blocker+, Blockerz, BlockIt, Blockster, BlockuPie, Bolt, Breezeblock, BYO Blocker, Calm, Cerberus, Chop, Clean Explorer, Cleanse, Clear, Clear +, Cookie Stumbler, Cookies Notice Blocker, Crowdblock, Crystal Pure, Cube, Destilled, Discontent, Earmuffs, Extreme, F-Secure AdBlocker, Faster Web, Flare, Free Ad Blocker, Green Duck, Greerow, Halcyon by Daniel Zakork, Handblock, Hopdeck, ibBlock, iBlockify, Image Blocker by Iaroslav Arsenkin, Image Blocker by Koji Iino, Image Blocking, Jblock, Just Block, Ka-Block!, Kitten Block, LemonBlock, Lurker, Magic, Mr. Adblock, Mr. Crumble, Neat, Neutral, No Ads, NoThirdParty, Oasis, Oppilo, Parental Control, Pirade, Porn Blocker Pro, Presto, Privacy Content Blocker, Private Browsing, Quartz, Quiet Blocker, Ranger, Roadblock, Rocket, Samurai, Sans Fonts, Script Blocker, Shield, Simple Ad Block, Skynet, Speedafari, Speedy Blocker, Stop AD by Jane Bin, Stop Ad by Kirill Kudin, Stop Ads by Denys Yevenko, Stop Ads by movin’App, Super Ad-Blocker, Super Blocker, Surfguard, Swab, ÜberBlocker, Unity, WebWipes, Wipr and 広告ブロックするんです. I also left out malware content blockers for Android and an artsy blocker with a scurrilous name. Surely this list will grow over time.

In the last few months the vast analysis of adblocking has concentrated on connecting the sovereign control of users to ad tech. But having an overview over the twenty-five content blockers comes with a surprise. The culture of filtering the net can be more diverse than just blocking advertising or tracking scripts. Content blocking tools might have political power. Anthropologists, sociologists, media and political scholars will look into the impact of public movements towards net regulations: Do Internet users merely hate the UI of the European cookie warnings or is there a deeper meaning to its elimination?

Dutch EU cookie warning on the homepage of the online newspaper trouw.nl

Balancing the web where every single element can lose its status quo by content filtering and alteration will be a particularly tough challenge. The transformation process from the 1998' Webwasher to the 2015' content blocker can no longer remain a single debate about online advertising. Sadly, looking at related work on filters (e.g. spam filters, noise cancellation), sociology of filters (e.g. filter bubble, filter sovereignty), tracking (e.g. ad tech, ad fraud), countermeasures (e.g. anti-adblocking, ongoing discord in courts), art (e.g. drones adbusting ads, Sadblock), advertising blocking (e.g. banner blindness, DVR) and others — the secrets of adblocking are not nearly uncovered. The main question remains open: Every mind comes with a build-in blocker, why outsource that control to machines? Clearly, these is need for the science of adblocking software and hardware, there is desire to name its purpose.

Proposing the inevitable — here is Controlonomy. The effort behind Controlonomy should not only involve a backup of the source code, filter lists and hardware for research purposes. The rational pro and con sides, the hate and love of content blockers and especially the advertising of such software will be important and must be saved for later generations. They will want to view the full collection, to understand why the mind turned to filters and how the filters turned into a mind. For the scientists and tech enthusiast looking at the old content blocking from 2015, I really hope the science of adblockers can preserve as much of the digital filters as possible. Let’s just not name it Controlonomy, yet.

I would like to thank The Brooks Review, The Loop and MacRumors for their effort to search and review content blockers. Much appreciation goes to P., E. and W. for making smart suggestions and proofreading this peace.

@nattsuhon currently works as a graduate assistant at a German university. His research focuses on web filters, the history of the Internet and facial recognition. As a speaker he prefers the talking formats of science slams and barcamps.

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