I found todo apps to be clunky and bloated. I decided to use github issues (of a private repository) as my notes. I even made a little script around it (via gh-cli) to edit it from the command line [1]. I don't update TODO very often from my phone, but in case I want to, I use the Github mobile app. I am finally content with this solution (although I don't know for how long).

[1] https://github.com/bojle/note.py