There are lots of online resources for learning Android - Pluralsight, Udemy, Treehouse and going through the Android dev basics site https://developer.android

There are lots of online resources for learning Android - Pluralsight, Udemy, Treehouse and going through the Android dev basics site https://developer.android.com/training/basics/firstapp/ https://developer.android.com/training/basics/firstapp/ Not sure what you mean by "clean". APIs and Frameworks are always evolving. You have to keep up to date and understand the main problem sets that are part of the platform (loading Bitmaps efficiently, activity lifecycle, etc.). And no Fragments are not being discontinued. You are probably referring to the guidelines to use the support Fragment library instead of the older Fragment classes. I build mobile apps for a living and if you want long term stability and performance, my advice would be to go native with Java/Kotlin. If you ever want to build for iOS it's not that hard to pick up Swift/XCode - the platforms become more and more similar as they evolve. There are plenty of people using RN and maybe Flutter too but all the mobile devs I know who work for clients and / or ship their own apps use Java / Swift. Feel free to comment if you have more questions. Enjoy!