Slack - A messaging app for teams who see through the Earth!
Muzzle - Silence embarrassing notifications while screensharing
Smoothboard Air - Smoothboard Air is a collaborative interactive whiteboard application for iPads and Android devices that revolutionizes interaction in lecture rooms.
Upscope Screen Sharing for Intercom - No-downloads screen sharing fully integrated with Intercom.
Groupboard - Free collaborative online whiteboard, web conferencing and online tutoring software that can be embedded in your own website. Used by many online tutors, schools and universities.
Dead Simple Screen Sharing - Simple screen sharing and audio conferencing software.