If you subscribe to Jerry Seinfeld's Don't Break the Chain productivity method, this Android app might help you out. Called Day by Day, it helps you mark off each day you spend time working on a goal. The app can help remind you to do said activity per day and shows a check mark if you achieve it. If you don't, then you break the chain. The app lets you add to goals for free. If you want to add more, you need to pay US$1.50.
Source: Lifehacker