Habitica 

Habitica (formerly HabitRPG) lets you turn your life into a classic role-playing game: design your character and level up as you complete real-life tasks. There’s lots of little goodies like pets you can collect and level up, items for your character, etc. But it’s all connected to things you want to do in the real world.

Did you really complete that task? That’s up to you being honest – or you can form a party with other players who can hold you to account if you’re not telling the truth. The game can’t punish you in real life (unlike systems designed around commitment contracts, like Beeminder), but it does reduce your hit-points if you fail to meet your commitments for the day.

Overall it’s a playful take on to-do lists; I used it for a while and found it fun but eventually grew tired of it. The RPG bits aren’t so well done that they really draw you in, so you’re left with a to-do list with pets and levelling. With that said, it’s a very active project – definitely worth checking in, or looking at again if you haven’t in a while. 3.5 stars, rounded up because it’s an open source project.