Good Habits is just the right mix of practical and fiddle for my taste. I've got a nice list of habits I'm working on in there and I find it very satisfying keeping my momentum going as I open it at the end of the day and check off things. Several of my daily tasks from OmniFocus have transitioned over. These include things like flossing teeth, checking banking site, logging food, and doing something (anything) on a MacSparky Field Guide. These never felt like tasks so much as habits and I'm glad to have them out of my OmniFocus database.
Anyway, the app is free and if you are looking for a way to give yourself a little geek-motivation, I recommend it.