With Xcode 4 you can develop applications for iPad and iPhone. Also, you can choose a different iOS target. Currently, the last release of iOS is 4.3 and when you will create a new project you will see:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  // Override point for customization after application launch.
  self.window.rootViewController = self.viewController;
  [self.window makeKeyAndVisible];
  return YES;
}

Now, the rootViewController property has been added with iOS 4. This means that when we going to test the application in iOS 3.2 environment we will get a CRASH! Instead of check the iOS version, we can use a feature of Obejctve-C in order to check if a property exists:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  // Override point for customization after application launch.
  if ([self.window respondsToSelector:@selector(setRootViewController:)]) {
    self.window.rootViewController = self.viewController;
  } else {
    [self.window addSubview:self.viewController.view];
  }

  [self.window makeKeyAndVisible];
  return YES;
}

As usual, please don’t hesitate to leave any questions or comments in the feed below, and I’ll aim to respond to each of them.

If you  would like to avoid to set the background image of the main view controller through Interface Builder, you can use a different way and delete the UIImageview object from Interface Builder:

- (void)viewWillAppear:(BOOL)animated 
{
  [super viewWillAppear:animated];
  self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"backgroundImage.jpg"]];
}

You may use viewDidLoad as well but viewWillAppear avoid some flickering. With Xcode 3.2.5 is not possible to use the pattern yet.