[AbstractFactor]

If you know Java, Android can be programmed in Java or Kotlin (a Java like JVM language).

A lot of Android is not front end. SQLite databases, models, maybe use cases, JUnit unit tests etc. You know how to do a DAO to MySQL, Oracle or Sqlite? You know how to do a JUnit unit test of a data structure? That part will be easier then.

Keep UI simple - one Activity, Navigation and Fragments. Use a ConstraintLayout and simple views like TextViews. Use a popular, simple image library.

Much of Android work is not UI work. Keep the UI simple initially.

[dehrmann]

Most of the Android-specific stuff is around app lifecycle and yes, UI. And you're right that a lot of this isn't so different from backend Java.

I'd suggest OP download Android Studio. It's based on IltelliJ, so there's a good chance OP will feel right at home.