One possible approach is starting with a Cocos2D project and then using CCUIViewWrapper to display any view as a CCNode
. This approach is the best one if you can handle all of your views inside of the same Cocos2D scene.
If you are planning of building, e.g., a navigation controller based app, then the opposite strategy could be more adequate: start with a "normal" app and then, when you need it (i.e., in your third view controller), add Cocos2d's GLView to your view controller view:
[myViewController.view.layer addSublayer:[[CCDirector sharedDirector] glView].layer];
or:
[myViewController.view addSubview:[[CCDirector sharedDirector] glView]];
You will need to import QuartzCore/QuartzCore.h to be allowed to use CALayers.