Berkanan - Chat with people nearby. Even offline, on an ✈️.
Roomvine - Chatrooms for real life venues, neighborhoods and events
Stealthy: Secret Messenger - Chat anonymously with friends & strangers
Spectrum - Browser-based app to visualize the frequencies of an audio file.
SuchApp - A messenger that lets you discover new people
CityBugs - Improving cities to make them a better place to live in.