Roomvine - Chatrooms for real life venues, neighborhoods and events
Spectrum - Browser-based app to visualize the frequencies of an audio file.
Jodel - What is Jodel all about? Jodel is the community that shows you what's happening in your area in real-time.
Treadie - Create your own micro-social network for topics
Yakko - Anonymously post, comment, and interact with people at your university.
Carrd - Simple, responsive one-page site creator.