SmartDraw - Instead of starting with a blank screen, SmartDraw gives you the exact template you need.
Slack - A messaging app for teams who see through the Earth!
Creately - The new interface for work to ideate, plan, and execute
Smoothboard Air - Smoothboard Air is a collaborative interactive whiteboard application for iPads and Android devices that revolutionizes interaction in lecture rooms.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
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.