Question

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease];
    self.navigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];
    self.window.rootViewController = self.navigationController;
    [self.window makeKeyAndVisible];
    return YES;

Answer 1

Try out this to remove the navigation bar.

(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease]; 
   // Override point for customization after application launch. 
   MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease]; 
   self.window.rootViewController = masterViewController; 
   [self.window makeKeyAndVisible]; return YES;
}