AndroidExercises
My exercises with Android
Start Android for beginners (RU)
Coding for Android (RU)
http://developer.alexanderklimov.ru/android/
How to make an Android application yourself (RU)
https://skillbox.ru/media/code/kak_sdelat_prilozhenie_dlya_android/
Making Android BLE work (RU), Mar 23, 2019
https://habr.com/ru/post/536392/