[divbzero]

todo.txt accomplished this with community apps that provided web and mobile interfaces to the text file: http://todotxt.org/

[notdiaphone]

The problem is that most those tools end up unmaintained.

[dddw]

Yeah, simpletask

[tero]

SimpleTask Cloudless has been my favourite todo.txt app for Android. Unfortunately, SimpleTask is in low maintenance mode [1], and does not work well in my setup.

According to mpcjanssen: "The suspending of the applications by Google #1102 and the continuously fixing breakage by Android API changes have reduced my Simpletask motivation to a very low level." [1].

[1] https://github.com/mpcjanssen/simpletask-android/issues/1110

[notdiaphone]

I'm not sure it's even in maintenance mode at this point. I wish I had the skills to maintain it as I quite like SimpleTask and may, even if unsupported, go back to it. Nothing compares on Android.