UBlock

UBlock is an iOS app that allows users to select apps they consider distracting, create a list of productive alternatives they’d rather commit their time to, and set a schedule during which the distracting apps are blocked via the Screen Time API’s App Shield. The app’s functionality is centered around one main screen, where the user can view their personal configurations and choose whether or not to edit them. The screen is divided into three sections: “Distracting Apps”, “Productive Alternatives”, and “Schedule”. Once saved, the schedule enforces itself in the background, whether or not UBlock is ever opened again.

During July 2021 through December 2023, one-half of teenagers ages 12–17 had 4 hours or more of daily screen time.¹ Excessive use has been associated with negative mental outcomes including depressive symptoms² and disrupted sleep,³ and the problem is only progressing as devices become more accessible and are used by younger demographics.

Many of the features meant to address this issue are ineffective by design. The screens displayed by various providers often have buttons that allow users to bypass the limit. Court filings against TikTok and Meta, and Apple’s own support forums, show how little these features do.

Before I designed any screens, 34 people answered the same set of interview questions, most of them college students along with a few working adults. Over 95% wanted to decrease their screen time. Only 2 had installed a screen-time app — and both uninstalled it due to the app being ineffective at reducing screen time.

The same few patterns kept coming up across the interviews:

Reading 100 App Store reviews across 5 different apps revealed what users like and dislike about screen-time apps already on the market. Price, setup, and how easy the block screen is to get past came up again and again. None of the apps truly redirect users to pursue their own personalized goals, and most remain easy to bypass.

Discovery showed that people wanted to be redirected towards their own goals, and that reducing screen time is social. When I pitched UBlock in my entrepreneurship capstone, a visiting entrepreneur suggested gamification to make the app “sticky,” so I sketched a version where repeatedly completing healthy habits allows users to level up a virtual avatar and decorate a home their friends can visit. My capstone advisors also warned that customer acquisition would be my biggest hurdle, and suggested encouraging competition between friends. This resulted in a leaderboard that encourages users to compare their screen times with friends, supported by a profile screen for adding them. The home screen leaves everything else user-defined, since every smartphone user has a different definition of what truly is too much time spent on screens.

Gamification was dropped in favor of a more streamlined social experience, as encouraging people to continuously return to an app that’s supposed to limit distractions defeats the idea of getting people off their phones in the first place. The leaderboard, on the other hand, rewards whoever spends the least time on their phone, and builds on what interviewees were already doing to hold each other accountable. Since it would only function when a user had friends that also used the application, it would also encourage users to invite their friends to download the app, addressing my advisors’ concerns with customer acquisition. As such, the leaderboard became the primary feature I set out to build, until Apple’s privacy limits ruled it out as well (see Engineering).

Apple represents 57.93% of the U.S. mobile vendor market share,⁷ so I built UBlock for iOS using Swift, SwiftUI, and Apple’s Screen Time API, with Firebase intended to handle user accounts for the leaderboard. The app is split into three programs that share their data, so blocking keeps running on schedule even when UBlock is closed.

In programming the application, it became quickly apparent that the leaderboard could not work as designed. Apple runs most of its Device Activity features in a sandbox environment that does not let developers obtain access to an iPhone’s usage data, so the profile and leaderboard screens were scrapped. The App Shield would have been the best place to show users their own goals, but it runs in a sandbox environment as well, and its configuration cannot be adjusted outside of the title, subtitle, icon, and button. Thus, the shipped shield simply tells users to look at their to-do’s.

UBlock offers promising functionality in its minimum viable product state, and can already be used by others to help them reduce their screen time on distracting apps. By the end of the semester, 34 people were willing to beta-test it.

Customer discovery proved to be an excellent vehicle through which one can avoid spending money and time building something that no one wants, and software development proved inherently hard to plan, especially solo. My biggest takeaway, though, is that due to the existing implementation limitations, exploring how to create more friction between users and their blocked apps seems to be the path forward. The goal is to increase friction beyond what existing first- and third-party solutions supply, while avoiding a level so restrictive that it convinces people to delete the app to get around it.

Moving forward, I plan to keep improving UBlock in a few key ways: