Simpletask Cloudless might be what you're looking for. It uses todo.txt, which you can sync via Nextcloud (or whatever other provider), and has in my opinion th

Simpletask Cloudless might be what you're looking for. It uses todo.txt, which you can sync via Nextcloud (or whatever other provider), and has in my opinion the best functionality of any android todo app. The downside is that its onboarding UX isn't great, and overall it's not as polished as some other todo apps. I've done some work on it in the past and would like to find time to do more in the future. https://github.com/mpcjanssen/simpletask-android https://github.com/mpcjanssen/simpletask-android