MyLifeOrganized runs on Windows and Android, has templates to setup GTD, Franklin Covey, DoItTomorrow and even the Fly-Lady's Control Journal profiles.
The GTD templates, there are two, are very complete, haven't played with the other templates yet.
Started as a Windows program, so very mature on that side. The Android app is still in Beta and is free for now. No bugs that I've found, just not all the editing features for the tasks that are available in the PC version.
They have MLO apps for iOS, Blackberry and PocketPC as well.
It has a couple of sync options as well. One is cloud.
So far it has been a stellar app, I plan to purchase the PC version shortly and the Android app when it comes out of beta.