transitionWithViewDemo.m

-(void)viewDidLoad{
    [super viewDidLoad];
    UIButton *btnFlip = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btnFlip.frame = CGRectMake(10, 10, 50, 30);
    [btnFlip setTitle:@"flip" forState:UIControlStateNormal];
    [btnFlip addTarget:self action:@selector(flip) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btnFlip];

    panel = [[UIView alloc] initWithFrame:CGRectMake(10, 40, 300,300)];
    panel.backgroundColor = [UIColor darkGrayColor];
    [self.view addSubview:panel];

    panelBack = [[UIView alloc] initWithFrame:CGRectMake(10, 40, 280, 200)];
    panelBack.tag = 1;
    panelBack.backgroundColor = [UIColor brownColor];
    [panel addSubview:panelBack];

    panelFront = [[UIView alloc] initWithFrame:CGRectMake(10, 40, 280, 200)];
    panelFront.tag = 2;
    panelFront.backgroundColor = [UIColor whiteColor];
    [panel addSubview:panelFront];

    displayingFront = TRUE;
}

-(void)flip{

    [UIView transitionWithView:panel 
    duration:0.5
    options:(displayingFront ? UIViewAnimationOptionTransitionFlipFromRight : UIViewAnimationOptionTransitionFlipFromLeft)
    animations:^{ 
        if (displayingFront) {
            //panelFront.hidden=TRUE;
            //panelBack.hidden = FALSE;
            [panelFront removeFromSuperview];
            [panel addSubview:panelBack];
        }else{
            //panelFront.hidden=FALSE;
            //panelBack.hidden = TRUE;
            [panelBack removeFromSuperview];
            [panel addSubview:panelFront];
        }
     }
     completion:^(BOOL finished){
         displayingFront = !displayingFront;
     }];
}