Well, in particular he states two things that are worth noting: 1) You have to hand code all your interfaces. The SDK uses Interface Builder, which lets you

Well, in particular he states two things that are worth noting: 1) You have to hand code all your interfaces. The SDK uses Interface Builder, which lets you 'draw' your UI similar to building a normal Mac app. 2) He's using a Javascript interpreter to create the UI. Unfortunately the SDK doesn't allow 'interpreted languages': "3.3.2 An Application may not itself install or launch other executable code by any means, including without limitation through the use of a plug-in architecture, calling other frameworks, other APIs or otherwise. No interpreted code may be downloaded and used in an Application except for code that is interpreted and run by Apple’s Published APIs and built-in interpreter(s)." Javascript may be a fuzzy point if Jiggy doesn't use only apple's internal/native stuff. Plus, I notice Jiggy still lists itself as requiring a Jailbroken iPhone. Cool stuff, but not sure if it's usable on the SDK for those building mainstream apps.