SpaceX Falcon 9 Lander - Try (and fail) to land Elon Musk's SpaceX rocket
Tremendous - Tremendous is a customer and employee loyalty platform that allows companies to reward their customers for surveys promotions and referrals.
SpaceVR - Explore space with Oculus Rift (pre-launch)
Giftbit - Buy, send and track digital gift cards for your reward and incentive programs.
The Size of Space - An interactive visualization of the universe
Rybbon - Send digital e-gift cards as marketing incentives or rewards with Rybbon, which integrates with Marketo, HubSpot, SurveyMonkey, and Qualtrics.