The programming language for the first generation of Android app development was Java.The programming language that will dominate the second generation of Android app development will be Kotlin.Kotlin is a powerful language, designed to be concise yet expressive, both for application code and for libraries. However, some of that comes at a cost, as Kotlin has a lot more keywords and specialty features than does Java. A lot of that complexity is only needed by intermediate to advanced Kotlin developers, though.