It's possible that it still runs on iOS 10 beta, but based on their sample templates and what they have used in WWDC16, it's already a fully functional app. Better implementation than Tynker. And it's also a good preview for future coders to use.
Yeah, and it might even be the best choice to use it. I'd guess it would be. But it feels against Apple's "house style" to use unreleased software in that way.