iOS 8: UINavigationController hide back button

Question

After I run my application in iOS 8 (XCode 6.0.1, iPhone 6), the back button does not hide.

My code:

- (void)removeCategoriesButton
{
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        [_navigationController.topViewController.navigationItem setHidesBackButton:YES];
        [_navigationController.topViewController.navigationItem setLeftBarButtonItem:nil];
    } else {
        UIViewController *controller = _app.window.rootViewController;

        if ([controller isKindOfClass:[UINavigationController class]]) {
            UINavigationController *nav = (UINavigationController *)controller;
            [nav.topViewController.navigationItem setHidesBackButton:YES];
            [nav.topViewController.navigationItem setLeftBarButtonItem:nil];
        }
    }
}

But the back button does not hide (see screenshot):

UPD:

I run application in another simulators, and i see this "bug" only on iOS 8.

Answer 1

This worked for me.

-(void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    [self.navigationItem setHidesBackButton:YES];
    [self.navigationItem setTitle:@"Home"];
}

Answer 2

I tried many of the answers but the only one that worked for me was:

    override func viewDidLoad() {
    super.viewDidLoad()

    let backButton = UIBarButtonItem(title: "", style: UIBarButtonItemStyle.Plain, target: navigationController, action: nil)
    navigationItem.leftBarButtonItem = backButton
}