Whereby (formerly appear.in) - Collaborate from anywhere - video meetings with no downloads
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Brie.fi/ng - Start secure group video chat
Keybase Chat - End-to-end encrypted chat built into Keybase
MeetSpace - Video conferencing for teams that doesn't suck
Crypho - End-to-end-encrypted messaging and file sharing