This is, quite simply, incredible. My team was looking for something to replace Pixate even before Google announced they were shutting it down, and just having watched the first tutorial, it feels like we're done looking.

I feel silly jumping to a nitpick at this point, but I see one obstacle for my team: There doesn't seem to be a way to enter custom screen sizes, apart from eyeballing it with the resizable window setting (we're designing for a custom-built Android device). That's probably not enough to stop us from using it, but it would be great to have the option.