Explain Everything - Explain Everything is an easy-to-use design, screencasting, and interactive whiteboard tool that...
Scribble Online Whiteboard - Scribble Online Whiteboard is an advanced collaborative whiteboard solution that allows you to draw the sketch using the web-based or mobile platforms such as iPad/iPhone and Android.
Microsoft Whiteboard - The canvas where ideas, content, & people come together.
Ryeboard - A practical and visual workspace for modern teams
Conceptboard - Instant Whiteboards for Teams & Projects
Whiteboard Team - Draw, explain and collaborate visually in real-time.