Love the idea of this app I think it solves a lot of issues that Lucid Chart has, the only question I have is if the free plan includes collaboration with other people in realtime? If so, some feature requests I would recommend to make it next level for developers are:
1) Making this an add on to IDE's. Similar to what codestream does.
2) Integration into workspaces (i.e. Google Drive).
I'm sure I will have some more after I use it, but all in all, this is really cool.