If you're a Fitbit user, Tappy Fit (free) will help you get to that 10,000 daily step goal with in-game incentives. The game reads your Fitbit data, so if you walked 10,000 steps that day, then the pipes will open up extra wide. If you take fewer steps, the space between the pipes gets more narrow.
Tappy Fit is a working game, but it's also an experiment. The Small Steps Labs is working with subtle ways to keep health-conscious users engaged with their step readings on wearable devices like Fitbit.