Roomvine - Chatrooms for real life venues, neighborhoods and events
Stealthy: Secret Messenger - Chat anonymously with friends & strangers
Jodel - What is Jodel all about? Jodel is the community that shows you what's happening in your area in real-time.
Vuash - Send secret messages safely.
Yakko - Anonymously post, comment, and interact with people at your university.
Phonebot - Make phone calls from within a Slack channel