I use Google tasks for my todo list. This GNOME extension is nice and minimal and just what I'm looking for, and it uses todo.txt. Is there an easy way to sync my changes with Google, similar to how the GNOME calendar app does?
EDIT: Endeavor (GNOME "To do") seamlessly integrates with Google Tasks and ostensibly todo.txt but I can't get it to recognize the todo.txt (I'm not sure it would sync todo.txt > Endeavor > Tasks even if it was working, however).
I'm afraid you can't
The calendar shares information due to CalDav compatibility, however I don't think it applies to Tasks as well, since we don't even know what protocol Google Tasks uses
I think the best you can do is use the Todo.txt app on your phone and sync it through Google Drive to have access in both your phone and your PC
Endeavor (aka GNOME "to do") seamlessly integrates with Tasks, so it's definitely possible.