Flare by GoDaddy - Discover, give feedback and support startup ideas
Idea Hunt - Solve specific challenges for your favorite products
Wittycircle - Networking tool for entrepreneurs, makers and curious minds.
Flopstarter - A platform for bad ideas
Pitchstack - Become an armchair VC and judge the pitches of the day
Xmind - Xmind is a brainstorming and mind mapping application.