This is RubyMotion's biggest problem right now. All of the examples are nearly 1:1 of ObjC code, and they require you to already know the iOS SDK. For someone who already knows Ruby and iOS programming, it might save a few keystrokes here or there.

This specific example saves some code over building the app from scratch in straight ObjC. But, you could get the same savings with a regular ObjC library that does the same thing, too.