There are some errors in there:

     // The UIApplicationDelegate protocol requires you implement this function. 
     // It will return our main UIWindow so the application (UIApplicationMain from main.m) 
     // knows where to start.
     - (UIWindow *) getMainWindow;

That's simply not true. There's no reference to getMainWindow in the Apple docs nor in UIKit, I've just examined the binaries. In fact, Apple's conventions state that getter methods don't have the "get" prefix, so if it existed it would be called just "mainWindow".