When it asks you to sign in, use your Scratch username. The rest is in the project.
I've seen a lot of "OS's" and I thought I should try it out... and it is much different than other ones I've seen. So far it does pretty much nothing (It will as soon as those fancy cloud lists come out) so this is just the main structure. And I do realize it's a bit bland, but hopefully it will have a programming language similar to scratch... which shouldn't be a problem :D If you like it, you know what to do. :D