I checked it out and created a diagram, then I clicked the icon in the upper left corner thinking it was some sort of menu. But it just took me to the main home page -- but without saving anything at all or even prompting me. So I basically lost all the work I did without warning. Is that supposed to happen?

> Create as many diagrams as you want. Save your diagrams locally to pause and continue later.

I found the save button, but it seems to just take a single snapshot and reload that automatically if I leave and return. So it seems like you can only have one diagram going at a time? But even if I want to start a new diagram, I can't figure out how to do that without manually clicking each individual icon and deleting them, one-by-one.

Maybe I need to signup for this additional functionality to work?