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];