When I worked at Rosetta Stone as a iOS software engineer circa 2015, I wrote a couple of short blog articles to illustrate some UI techniques that we used in our apps.

Rosetta has shut down the site contining these articles, but I have a copy here for posterity.

These are from the iOS 7 era, so there are possiblly better techniques at this point.

Interactive Card Flip Animation Techniques

Specializing View Controller Animated Transitions in iOS 7