It seems like Apple’s motive is to discourage technologies that abstract away phone specific API’s and make it easy for developers to write once and compile/deploy on multiple smart phones. It makes sense for Apple to do this since iPhone is the market leader, and most apps would need to target iPhone first before other smart phones, so why make it easy for them to be ported to other smart phones, and thus eroding Apple’s huge lead in the number of apps?

Adobe’s Flash is such technology, but MonoTouch, as I understand, is not so much an abstraction but a C# wrapper around Cocoa Touch API’s; developers still need to learn Apple specific API’s. I suspect that Apple’s may be only targeting the write-once technologies, and different alternate development methods may get different treatments in terms of the enforcement of the rule.

Of course, a “twitter search” app here just happens to be the type of app chosen for the example built, so yes, each situation may call for a different approach.

On the other hand building a native app to search twitter on multiple platforms sounds like too much work. I’d rather build a mobile website or a phonegap/sencha touch etc. app if a mobile app is required.

Of course, as always it depends on your situation. I generally would like to avoid maintaining a code base per platform for the same app.

Of course, if you want to throw in / then you are in trouble, and that’s what the poster is about