Javalin

Kotlin can be used for any type of development: from server-side and client-side web to Android and iOS . The language runs on JVM, which enables code sharing between different platforms. Similar to React Native, it offers developers a great perk of reusing existing codes, which saves them a lot of time and energy.

The top three frameworks reflect the dominant usage of Kotlin for Android and web development, with Kotlin Android Extensions the most popular, just behind that is mockito-kotlin for use with the Mockito mocking framework for unit tests, and then RxKotlin for use with the asynchronous programming library RxJava .