ToT: ThisOrThat - Let your friends choose this or that for you
Go Fucking Do It - Set a deadline and a price. If you fail, you pay.
sup - The first creep-free way to see nearby friends
Decidr - Make better decisions with quick A/B polls
Zenly - Zenly is a GPS tracker to locate your friends in realtime.
AbTest.io - A free url shortener with A/B testing features