My team for Startup Weekend Hong Kong did something similar as well [1], and we're still planning on bringing it to market.
Our goal was to use charity to incentivize people to form habits - we started with exercise, but it could easily extend to things like quitting smoking or spending more time reading. When you sign up with our app, you choose two charities - one that you like and one that you don't - and if you stick to your commitments, we send your money on (minus our overhead fee) to the one you like. If you don't stick to your commitment, we send your money to the other one.
Our goal was to use charity to incentivize people to form habits - we started with exercise, but it could easily extend to things like quitting smoking or spending more time reading. When you sign up with our app, you choose two charities - one that you like and one that you don't - and if you stick to your commitments, we send your money on (minus our overhead fee) to the one you like. If you don't stick to your commitment, we send your money to the other one.
I see this as a great bit of market validation.
1. http://www.slideshare.net/culturestate/promise-fit-slideshar...