Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Explain Everything - Explain Everything is an easy-to-use design, screencasting, and interactive whiteboard tool that...
Sketch - Professional digital design for Mac.
Conceptboard - Instant Whiteboards for Teams & Projects
Adobe Illustrator CC - Adobe Illustrator CC is a commercial vector graphics editor.
Microsoft Whiteboard - The canvas where ideas, content, & people come together.