How YO breaks the rules by letting users set their own


Handheld digital devices have made it possible for people to carry technology with them at all times. One of the most used social and mobile software is instant messaging, having a wide range of possibilities to choose from. Users often decide to go for the product that better adapts to their communication needs and also depending on its popularity. The bottom line is being able to have a direct and immediate way to communicate with friends, family, co-workers and more.

This critique’s aim is to understand why YO, a single-tap zero character communication tool, has become a big success in a market where other apps try to include as many features as possible. This analysis is made by exploring the outstanding power of indexicality that YO presents and the unofficial conversation rules that users have created for different contexts.


A considerable number of studies have explored the use of indexicality to inform design for user interfaces with an important focus on the relation between information and functionality. The following content will present and analyze valuable insights taken from significant literature referring to semiotics, context, indexicality and communication within CSCW, with the aim of understanding the importance of these concepts in the design of social and mobile software and how it affects the user experience.

Kjeldskov et al. (2010) describes an indexical as a reference that has a direct connection to an object and its location. While indexicality is a semiotics concept that depicts how an individual interprets representations within a context (Kjeldskov and Paay, 2010). When we place these concepts within the environment of social and mobile software its importance becomes evident because of how users tend to turn technologies as their own. This means that even though social software functionalities have been designed to perform specific tasks, user’s interpretation can change the way they are perceived.

To better understand the concepts of indexicality it is important to point out the difference between signs and indexicals. As described by Chandler (2007) a sign is a representation of an object which is interpreted by a person. While an indexical is a representation that has context specific meaning (Kjeldskov and Paay, 2010).

Another important aspect that is directly linked to the way users interpret certain features of social and mobile technologies is the context in which they are placed. Schidt et al. (1999) define context as a combination of human factors and physical environment. Human factors are formed by user information, social environment and tasks; while physical environment by location, infrastructure and conditions.

Most of the latest mobile technologies are built up with context-awareness features, such as: geographical location, time, position, etc. The data collected by these features help the software to display content that is better adapted to that context, however this responses lack the human factors that can’t be anticipated or predicted. This is where the indexicality complements the experience and presents user’s interpretation to the overall interaction.

Content presentation in a mobile digital platform has to be planned with special care because of the limited real estate. Context-aware technologies have done a great job by showing/hiding information based on the data collected, making the content more valuable for the user depending on the context. According to Kjeldskov (2002) if when displaying information the levels of indexicality are increased by using time and space data, the necessary icons and symbols to successfully communicate the information are considerably reduced. This guideline can help designers to translate the indexicality concepts into simplistic and cleaner interfaces, thus potentially improve the user experience.

Kjeldskov and Paay (2010) explain the idea mentioned before in a very straightforward phrase:

“Information already provided by the context becomes implicit and does not need to be displayed explicitly”.

Indexicality can have implications in the way users communicate in different scenarios which can be formal (work related, ceremonies, and interviews) or informal (idle chat, lunch, gossip). Social and mobile technologies provide users a wide range of tools to facilitate communication and also to improve the way to coordinate specific tasks or activities as many research studies related to computer-supported cooperative work (CSCW) have explored. Conversational dialogues between users and technology present cognitive issues while trying to learn how it works (Grudin, 1990).

CSCW studies have presented conversational insights in regards to turn-taking dynamic, where a structured communication pattern is often identified. Sacks et al. (1974) strongly believes that a characterization of turn-taking communication organization would be context-free and capable of context sensitivity. This will be mostly true when there is a set of communication rules that all participants are aware of. But in a context like social and mobile technologies used for informal conversations, the chance of users interpreting different content and features can result in ambiguities and misunderstandings.

Groupware mobile applications have a unique characteristic of been able to be accessed in different times and places. The context in which the users interact with the software opens the possibilities of perception; communication will also be altered depending on the unofficial mechanism or rules established by the users. This critique is introducing an evaluation of a particular social and mobile technology made for communication but primarily based on indexicality.


As in Google Play (2014), YO is a single-tap zero character communication tool for Android, iOS and Windows. The creators define it as “The simplest & most efficient communication tool in the world. YO is everything and anything, it all depends on you, the recipient and the time of the YO” (Google Play, 2014).

It is a social and mobile technology that lets users add friends and send them a ‘YO’ message with only one tap. The user cannot customize the message, this means that the main interaction is to send and receive YO notifications. There is also a list of automated notifications from external websites called “Index”, to know when something happens without having to visit the website (i.e. receive a YO notification when your favorite YouTube channel posts a new video). Lastly, the users can edit their profiles, invite and block other users.

The YO notification has its own sound effect (comic voice saying: ‘YO’) and will disappear once the user opens it. To send a YO to someone, the user only needs to tap the name on the friends list and it will be automatically sent.

Fig. 1. Home Screen: The main screen displays the list of users added to the app. One simple tap on a username will send the YO Notification to that person. The available options here are: adding a user, go to index and options menu.
Fig. 2. Add new user: When the “+” button is tapped, the user will be prompted with a text field to input the username and add it to the list of friends.
Fig. 3. Options menu: Available options within the app. They are: Invite and find friends, index, edit profile and unblock users.
Fig. 4. Edit profile: The user is able to change the username and the avatar picture to an image stored in the device or a new photo taken with the camera.
Fig. 5. Index: Subscription services to choose from to get YO notifications from external website activities. The first option lets users submit a new service to be created.
Fig. 6. Index categories: The user can sort the list of subscription services by categories. This facilitates the browsing task and helps finding a particular service faster.

As the figures show, the interface design is rather simple and minimalistic. Almost every screen keeps a similar structure (horizontal buttons) with color combinations. However, this layout could become a challenge for new users who are not familiar with the navigation.


YO presents itself as “the simplest & most efficient communication tool in the world” (Google Play, 2014). This statement may sound bold to the majority of people, but there could be found some truth in it when the user realizes that it actually depends on himself.

It is easy to understand why the creators give their product the title of: the simplest communication tool, because it takes nothing else than a single-tap to send the one and only message to someone. The user does not create custom messages, no images can be attached or links shared, it does what no other communication app does: the basic minimum. This attribute have made YO one of the most controversial apps in history, and even caused it to be called the world’s dumbest app (The Wall Street Journal, 2014).

Simplicity can be also translated to design; minimalism seems to be the foundation of the app’s visual style. The interface shows who you have sent a YO message and that is basically it (TechCrunch, 2014). But an important question arises: is this level of design minimalism intuitive? McKay et al. (2013) highlights the importance of intuitiveness over design objectives like simplicity, sometimes isn’t worth it. In the particular case of YO, a new user often finds himself lost in navigation. The similarity of appearance among the screens can confuse the objectives of functionality and even decrease the user experience quality, as shown in FIGURE 1 and FIGURE 3. However, it doesn’t take too long to learn how the app works and what there is to do.

On the other hand, YO’s self-given quality of being the most efficient communication tool (Google Play, 2014) is the main focus of the present analysis. The app market for mobile devices has a vast range of messaging and communication products, some of the most popular are: WhatsApp, Kik, Skype, SnapChat, Viber, Facebook Messenger (TechRadar, 2014). Most communication apps present similar features and add their own unique approach, such as SnapChat which introduced the first self-distructive messages (About.Com, 2014), but they all seem to try to increase their functionality overtime to better adapt to user’s needs. This can actually increase the likelihood of attracting more users but it can also generate discomfort in them because of the overwhelming amount of options and configurations.

It is common to see rules or conventions appear among communication mechanisms in different groups of people (Sacks et al., 1974), whether it consists on a collaborative environment or simply a friendly dynamic. A digital scenario, such as mobile communication technologies, is a very interesting place to see how people create and engage in different conversational mechanisms. Here is where indexicality becomes an important part of the understanding of how a minimal set of functionalities placed within a context can be perceived in particular ways throughout social interaction.

YO’s simplistic design successfully reflects the concept of reducing information representations by increasing indexicality (Kieldskov, 2002). As the creators describe: “YO is everything and anything, it all depends on you, the recipient and the time of the YO” (Google Play, 2014), letting the user figure out why and how to use the app is its biggest strength. An interaction that before could have been seen as dumb and pointless (The Wall Street Journal, 2014) now appears to be more than clever, even ingenious. When a user adopts the use of YO as a mean to say “Good morning”, “I am here”, “Just got home”, “I am free, you can come now”, “Are you ok?”, or pretty much anything, he turns the app to be exactly what he wants it to. Now, how the person that receives the YO interprets that signal is directly attached to the context and particular pre-defined rules between each other. Forbes (2014) clearly defines this as “The key isn’t the message itself, but the time and name behind it”. The possibilities are endless.

Personal experiences using the app in different contexts have shown that in most cases it is very important to establish rules in the first place. Testing the app with university colleagues without any goal often caused sending text messages through other apps. When a friend received an unexpected YO from me, he felt the need to text me or call me to find out what I wanted, even though there was no particular reason. On the other hand, when meaning was attributed by consensus, a simple YO was enough to send through a specific message to my family on the other side of the world. If I sent a YO in the morning, my relative would know that I was ready to Skype. But if I did it in night time, they would know that I wanted to know if they had any news about a family matter.

Communication has become more intimate and personal than with other apps by acting as a background tool that does the least to interfere with the conversation. Some YO messages actually said more by not saying anything at all.

The indexicality potential of YO is not only reserved for intimate personal communication. YO has been combined with one of Internet’s most handy tools, the cloud-based scripting service IFTTT (The Next Web, 2014), this allows YO users to get notifications when external services or websites perform a specific action. Going a little further, the future of YO places it in customer service interaction like Starbucks staff asking buyers for their YO username so they can notify them when their coffee is ready without having to call their names (Forbes, 2014).

The fact that the app gives the users the control to make it do what they want it to do opens a great deal of possibilities. Not only for the future development of the technology, but also for new creative ways for people to adapt it to their own social interactions.


This critique has described and analyzed the YO app from a design perspective as well as a functional and user perspective. The focus has been mainly on the high level of indexicality that this rather simple social & mobile technology has and how the users interpret the meaning and way to use it in for communication.

There is only one problem with the interface design, which while trying to achieve extreme simplicity falls into unnecessary usability challenges for the first time user. This issue could be addressed by applying color-coding and proximity principles into a re-design process (Ware, 2008), to group information into categories of functionality and thus make interaction smoother.

Either if the reason behind a YO is personal or just letting the user know that something important happened elsewhere, it is hard to deny that this revolutionary app has provided a brand new way for people to communicate through digital devices. In a world where social and mobile technologies are saturated with products that contain an overwhelming amount of features, the simplest communication app changes the rules by giving the users the power of adding their own meaning to a “meaningless” message. The true importance of the conversation is shifted to indexicality, and how a YO can be translated into different messages depending on the time, place, people involved and social conventions.

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