Add a mindmap feature
Add a way to create mindmaps https://www.wikipedia.org/wiki/Carte_heuristique to the Whiteboard software. That is very useful and simple solutions do not exist on the market.
Also make it possible to export the whiteboard in HTML, PDF etc formats.
The whiteboard could be enhanced to offer mind map elements. I am using FreeMind and if you operate this with a key board you will beat everyone in terms of elegance to use compared to any existing whiteboard elements. If you want to do a proper brain storming and structure the input in real time without others have to wait for you adopting the size of your notes sticker (available in whiteboard) this would be much better.