iOS 8 - weird behaviour on restore from background

[bivant]

iOS 8 (iOS 8 simulator only, works well on iOS 7 by default) - move app to background then to foreground:
text move at higher speed (then specified), text disappear on scroll finish

Fixed by adding UIViewAnimationOptionBeginFromCurrentState to
self.animationOptions = UIViewAnimationOptionCurveEaseIn;

also unclear why to observe UIApplicationWillEnterForegroundNotification if already track UIApplicationDidBecomeActiveNotification event