I built CollabUML after the need to work on designing systems with my peers, instead of screensharing, it's simpler to go into a website and start collaborating, it saves bandwidth which can be a problem sometimes, and it allows your peers to do edits instead of just telling you want to modify.
After thinking a bit and talking with people, looks like it can be useful for system design interviews.
I'm still thinking how to evolve it, if you have any ideas, let me know.
Be aware that anyone can go to any board, hence, avoid placing private information.
Thanks.