The Animation Collection (Long-term Updates)
Part of the reference project
https://github.com/schneiderandre/popping
https://github.com/facebook/Shimmer
https://github.com/moqod/iOS-Scratch-n-See
https://github.com/chiahsien/CHTCollectionViewWaterfallLayout
http://ronnqvi.st/multiple-animations/
https://github.com/jvenegas/TLMotionEffect
https://github.com/Flipboard/FLAnimatedImage
https://github.com/rFlex/SCViewShaker
https://github.com/JaviSoto/JSAnimatedImagesView