I've tried all of the Unixy tasks managers* and vim-tasks works well for me: https://github.com/irrationalistic/vim-tasks
Any file with .tasks turns into a todo list with keyboard shortcuts to create/complete tasks. Which is useful when adding them to projects on github.
I don't bother with trying to have one sync with mobile anymore. Simpler the better.
* I still need to try out org-mode