YouClap - Challenge and be challenged by friends and brands.
Grin Gaming - Grin Gaming is an adrenaline-inducing prediction app where you can win cash by answering simple questions during live events.
Spinnner - Challenge your friends to a spin-off (literally)
CAMelot - PDF table extraction for humans
UXTesting - Discover how your mobile users feel
The Prediction Game - Predict what'll happen in 2021, win a $1k fund :)