- (JVTransitionAnimator *)transitionAnimator
{
    if(!_transitionAnimator)
    {
        _transitionAnimator = [[JVTransitionAnimator alloc] init];
    }

    return _transitionAnimator;
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    // we need to tell our transition animator the current view controller & the new controller to be pushed
    self.transitionAnimator.fromViewController = self;
    self.transitionAnimator.toViewController = self.secondController;

    // enabling interactive transitions
    self.transitionAnimator.enabledInteractiveTransitions = YES;

    // also don't forget to tell the new UIViewController to be presented that we will be using our animator & choose the animation
    self.transitionAnimator.slideInOutAnimation = YES;
    self.secondController.transitioningDelegate = self.transitionAnimator;
}

// here is the trick if you want longer animations or set a delay or event not bouncing (known as dampling) at all
self.transitionAnimator.duration = 1.0f;
self.transitionAnimator.delay = 0.0f;
self.transitionAnimator.damping = 0.5f;
self.transitionAnimator.velocity = 0.9f;

// whenever you want to present the new view controller animated
[self presentViewController:self.secondController animated:YES completion:nil];