MySocialApp - Seamless Social Networking features for your app
Hamster Pad - A social network built on top of Slack
Manyverse - A social network off the grid
Kaboom by Hotspot Shield - Share messages & photos that disappear on any social network
Mastodon - Mastodon is a decentralized, open source social network. This is just one part of the network, run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome!
Tsu - Social that pays