Happy to share
https://github.com/zsoltk/compose-router, which supports a single-Activity, Compose-only approach to write apps. Navigation is based on routing with sealed classes. Every routing level has its own back stack, and back press can be bound to pop it. There's ambient scoped savedInstanceState associated with every back stack element, so that when you go back in history, state gets restored as well. Latest addition is deep link based routing which adds a remote control to set the app into any pre-defined combination of routing states. Personally I find Compose to be a lot of fun to work with, and would love to see it drive a whole app, not just its UI.