Kotlin + Android studio?

Question

Android

Interestingly, the latest applications that have a million audience on Google Play are still supported on classic Java Android, or as soon as this simplified language appeared, everyone frantically began to redo their projects for it?

Answer 1

Why redo if Kotlin is interoperable with Java? They can be used in the same project together.
Translate the entire project to Kotlin - it already depends on the preferences, taste, time of the programmer / business

Answer 2

Firstly, it is not simplified, but simply more thoughtful. In some places it is more difficult.
Secondly, yes, they began to move. It is interoperable with Java, you can write in two languages. All new features on Kotlin, old ones are transferred as needed (Cmd + Option + Shift + K + slightly finished).
We have much more code in Kotlin in Yandex Maps than in Java.