I've really been enjoying HabitRPG. This is a online time management app, but here's the clever part it takes the form of a role playing game.
So when I do my tasks like writing, submitting a story etc, cleaning the house, doing my 10K steps I get rewarded with experience points, gold and treasure.
It's free to play, although there are option to buy more goodies for a small fee ( $5). I've been so productive all week, and that's because I want to see my little fella advance.
Ah, the things that can motivate you.