Draw on any webpage (pretty much) or on a background color of your choosing.
Are you a web designer or dev? Work in QA? Product owner? Whiteboard lets you draw directly on top of live webpages using a stylus, mouse, trackpad, etc. so you can make edits directly in your hosted environments.
You can use the menu to the left to change your settings (pen size/color, optional background, multiple layers that can be re-ordered). You can also hide the entire menu so it isn't in your way.
This sucker is definitely still in development as there are some pretty big feature gaps.
Still in the works:
1. Being able to actually save your work out to an image file.
2. Different pen/brush styles.
3. Being able to add different shapes (ovals, rectangles, etc.)
4. Add straight lines by selecting end points.
5. Multi-user collaboration maybe? (That one seems like it might be problematic, but who knows?)
Have fun! Let me know what breaks!