How do I create a Tinder type UINavigationController?

I went through some tutorials and sample projects to see how to create a UINavigationController like in the Tinder app. This is the best example I have so far: https://github.com/Tgy31/THTinderNavigationController

But the problem I am facing is that I am not going to animate buttons like in the Tinder app. Please check this image:

Does anyone know how to achieve this?