How does GameMaker compare to XCode/Objective-C for iPhone development? I have an idea of GameMaker being really easy to use, but rather restricted in its functionality, while XCode/Objective-C is a lot harder to use but of course as flexible as can be (by design). I am thinking about picking up a book on one of the two (GameMaker or XCode/Objective-C), as I would like to develop iPhone apps, but am finding it hard to figure out the pros and cons. Any input will be appreciated :) :)
You can develop almost everything with Game Maker, but why you shouldn't is because it has really bad performance. I have read lot of reviews telling about games done with GM that are completely draining the battery. I won't choose this option.
I would rather look for something like Unity3D who's badass, or something cheaper like Corona SDK. The best way is still by using the native tools like xCode for iOS, and Eclipse Java for Android. But that's a choice that depends of the amount of time you want to spend for the development.
Update: The way to go is cocos2d-x.