What courses for android development?

Question

Android

Good day, there was a desire to write an application for Android, the main task is just a desire, not earnings. The question is, what course can you advise in order to at least approximately understand how to do this? A video is desirable (necessarily in Russian), but a book is possible. It would also not be bad if the content in this course / book is built according to the type “from simple to complex *, otherwise I found courses, I don’t remember whose ones, and everything is random there, and where to start learning was not clear Knowledge of java is theoretical, I know the syntax, but the "chips" of the language are not