GTBee that is a TODO app that charges you money for not getting things done. It is integrated with beeminder. See this post for more information http://forum.beeminder.com/t/gtbee-for-android/777
The code is outdated with bugs. It was my first attempt at making a complete app in Android, and it shows. Methods are huge, communication between fragments and activites is done in almost every combination imagiable and there are no tests. The notification branch was my attempt to fix there problems, but it is not complete and probably even worse than master.
If you are looking to make this app stable I would consider just writing it from scratch yourself. However if you are undaunted feel free to contact me and I can maybe help explain some of what is going on.