PlugBrain is a free, open-source Android app that puts a quick math problem between you and the apps you waste time on. The more you scroll, the harder the math gets. Step away and it gets easier. No ads, no tracking, no account, and no internet permission.
LivingRoom is another layer above the Android Room persistence library. LivingRoom generates all the boilerplate DAOs, Repositories, ViewModels and the Database.