Кнопка в тулбаре/навбаре с красивой иконкой.

    UIImage *faceImage = [UIImage imageNamed:(screenLocked) ? @"Locked" : @"Unlocked"];
    UIButton *lockBt = [UIButton buttonWithType:UIButtonTypeCustom];
    lockBt.bounds = CGRectMake(0, 0, faceImage.size.width, faceImage.size.height);
    [lockBt setImage:faceImage forState:UIControlStateNormal];
    [lockBt addTarget:self action:@selector(lockScreen:) forControlEvents:UIControlEventTouchUpInside];
    lockButton = [[UIBarButtonItem alloc] initWithCustomView:lockBt];