Flare by GoDaddy - Discover, give feedback and support startup ideas
Concepts - Concepts is a digital design sketchbook for iPhone, iPad, iPad Pro and windows 10 devices.
Wittycircle - Networking tool for entrepreneurs, makers and curious minds.
Sketch Mirror - Preview your iOS designs directly on your devices
Pitchstack - Become an armchair VC and judge the pitches of the day
Collect by WeTransfer - Collect by WeTransfer is the best way to organize your ideas.