Years ago, Java dominated Android app development. In 2011, JetBrains introduced Kotlin, a statically-typed language running on the Java Virtual Machine. In 2017, during Google I/O, Kotlin was announced as an official language for Android development. This modern programming language gained popularity among Android developers, becoming the second most loved language in the Stack Overflow Developer Survey 2018.

However, does this popularity translate to real-world success? Can Kotlin be used in production without any issues? We'll explore these questions by looking at 10 great Android mobile apps written in Kotlin. From popular social services like Instagram and Coursera, to project management tools like Trello and note-taking apps like Evernote, we'll examine the top companies that have chosen Kotlin for their Android app development.

Kotlin's Rise to Prominence

Instagram, one of the most popular photo-sharing social services, made the bold move to switch from Java to Kotlin. They shared the pros and cons of using Kotlin in production at Droidcon NYC 2016, even before Google announced its official support for the language.

Coursera: A New Era in Education

Coursera, an educational company providing open online courses, chose Kotlin due to its similarities with Swift, a relatively new programming language for iOS development. This allowed for easier knowledge sharing between engineers, better communication, and more efficient overall development.

Trello: Efficient Project Management

Trello, a well-known project-management application, uses Kotlin for their Android app. They haven't fully converted their old codebase to Kotlin, but they're leveraging the great interoperability between Java and Kotlin to work with both languages simultaneously.

Evernote: Note-Taking Made Easy

Evernote, an app designed for note-taking, organizing, task lists, and archiving, integrated Kotlin into their Android client. For more information on their Kotlin integration adventures, check out Evernote's blog.

Basecamp 3: A Productivity Boost

Basecamp 3, an app that helps manage growing small businesses, is written fully in Kotlin. Their developers claim that choosing Kotlin resulted in a huge difference in their work comfort, quality, and speed.

Open-Source Projects: Building a Community

Several open-source projects have also adopted Kotlin for their Android development. Twidere for Twitter, an open-source 100% material design Twitter browser, has been written mainly in Kotlin. Shadowsocks, a high-performance cross-platform secured socks5 proxy, uses Kotlin for its Android client.

Simple Calendar: A User-Friendly App

Simple Calendar, a simple and fully open-source calendar with no ads or unnecessary permissions, is part of the Simple Mobile Tools suite, all written fully in Kotlin.

KotlinConf App: Showcasing the Language's Potential

The official conference application for KotlinConf, hosted by JetBrains, the creators of Kotlin, is, of course, written in Kotlin. What's impressive is that not only is the Android client written in Kotlin but also the web, server, and iOS application.

DroidKaigi 2018: Another Conference App Built with Kotlin

The official conference app for DroidKaigi 2018, a developer-first Android conference organized in Tokyo, was also developed using Kotlin. This demonstrates the language's growing popularity among Android developers.

Conclusion

Kotlin may be relatively new, but it has already been used by top companies in their Android apps. Open-source projects and community-driven initiatives have also adopted Kotlin, proving its success in production. As Java is here to stay, keeping an eye on Kotlin can boost your team's productivity and save you from many bugs that could easily emerge in a vanilla Java project.

All data presented was up-to-date as of 15/03/2018.