Slack - A messaging app for teams who see through the Earth!
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Smoothboard Air - Smoothboard Air is a collaborative interactive whiteboard application for iPads and Android devices that revolutionizes interaction in lecture rooms.
Sketch - Professional digital design for Mac.
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.
Invision - Prototyping and collaboration for design teams