Skype for Slack - Move your slack discussions to a group skype call
HandsFree 2 - Call and SMS in Mac using your Android phone via Bluetooth
Pingly - Your communication hub — Email, text & voice in one app
Whiteboard for Skype Interviews - Skype brings a whiteboard to Skype Interviews
Missive - Team communication app now supporting FB, Twitter & SMS
Slack - A messaging app for teams who see through the Earth!