gistfile1.m

//Create a ViewController 
NavRootViewController *navViewController = [[NavRootViewController alloc] initWithNibName:@"NavRootViewController" bundle: nil];

//Use navRootViewController as its root Controller
UINavigationController *rootController = [[UINavigationController alloc] initWithRootViewController:navViewController];
    
//set the navigation bar title
[navViewController setTitle:@"Root View"];
    
self.window.rootViewController = rootController;