Cryptgeon - Securely share self-destructing notes
Hamster Pad - A social network built on top of Slack
BURN.link - Send secure, encrypted, self-destructing messages
Kaboom by Hotspot Shield - Share messages & photos that disappear on any social network
1ty.me - If you need to send a password or some other form of simple but sensitive information to someone...
Tsu - Social that pays