The UIView animation API results in different CAAnimations being added to the layer on iOS 7 and 8. Changing the bounds of a view like this:
[UIView animateWithDuration:0.3
animations:^{
self.myView.bounds = CGRectMake(0, 0, 100, 100); // was (0,0) (200, 200)
}];
will result in one animation for the bounds
key path being added to the backing layer if you are running iOS 7: