For the last 30 minutes I've been checking out Apportable and am now installing it.
After going over the docs, I can't see whether or not UIKit is supported.
Is it? If so, what is the look and feel on Android?
It is not supported in the Starter (free) version (other than some rudimentary classes). It is supported in the Indie version and above, but it seems it is beta. See: http://www.apportable.com/pricing, where holding the mouse over "Advanded Frameworks" says it supports UIKit.