[javajosh]

First, don't believe the claim about just being a "prototyping tool". That's what any tool or library says when it's trying to be humble. This toolkit's sweet spot is PhoneGap & friends, clearly.

See, the need this fills (and apparently does a good job at) is to give front-end web devs resources to write UIs in PhoneGap that look just like Interface Builder apps. Why would you want to do this? Possibly because you don't have iOS coders. Or perhaps your coders are already familiar with the web, so why not re-use their skillz?

The assumption here is that a front-end web dev can get a native-looking iOS app together faster in PhoneGap than a native developer can get a real iOS app together. While that's not always going to be true, it is probably usually true. And for some apps (like, virtually anything that's just business-oriented and doesn't require crazy stuff), the difference will not be noticeable by end-users (although it might trigger an uncanny valley feeling).