I'm missing the benefit of this over iOS 7's Core animation. I guess support for earlier os versions is the big advantage but for me all my new work is on iOS 7+ only apps and I'm not sure this helps a ton for that.
The key difference as highlighted in the video introduction is that Pop animates arbitrary properties on the model layer, allowing for easily cancelable and continuous animation. This approach is contrary to the Core Animation's transactional model, animating only the presentation layer.
If you are referring to the UIKit keyframe animation API that was added in iOS 7, that API has existed for some time at the Core Animation level. Keyframes are difficult to get right, and don't model physical systems like springs very well.
