Another cool thing they did, is they built a Sandstorm.io app back in the day. There hasn't been enough interest for them to invest a lot of resources in updating it, but I still use draw.io on my self-hosted Sandstorm server too.

I've followed draw.io back since I met them at Google I/O in like 2010 or 2011, I think they were one of Drive's first third party apps.