Agree with last reviewer. Good app, poor support, Mac App Store also at fault.

Besides the issues below, sync has stopped working between the ios and mac versions of the app. Todo is a good basic app if you have less than 30 or 40 things and data corruption is not an issue. It has good potential, the developers could improve the sync problems and overall app issues and make it a great utility.
I upgraded to verion 3.0.4 from 3.0.2 on the App Store. The app stopped working with my supported OS version. I too was told they can reproduce the problem, but offered no fix, no previous version, just an offer to be a beta tester….(?) Software that was working and Ive paid for simply has stopped working. When you have your work and personal tasks on a software program, syncing between desktops and mobiles, going a week without it is a significant hiccup. Apple is also at fault for annihilating the last version of software updated from their App Store and offering no mechanism to download previous versions. At least on iOS apps you can pull updated apps out of the trash when they are upgraded to failure! Simply going back to 3.0.2 would fix the issue for me but this simple solution seems to be too difficult for Apple or the developers to arrange.

Bangbangboogie about Todo, v3.0.7