Playlist Machinery - Tools that help you create & organize your Spotify playlists
Keybase Chat - End-to-end encrypted chat built into Keybase
Playmoss - Create playlists from YouTube, Vimeo and SoundCloud
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Tune My Music - Transfer Playlists Between Music Services
Crypho - End-to-end-encrypted messaging and file sharing