Okay i've been fucked by several todos apps now, I think i'll switch to emacs and self-hosting...
- an open source self hostable implementation, even if they offer a paid instance to ease your life.
- an open format in which you can get your todos entries
- an offline client that will still work even if the online instance closes
Started to use it because of some HN comment suggested it and I am so happy to started this. The only todo system that really stuck with me over time.
Good luck to you^^