How animation in mobile apps is helping them be successful

If you observe then you will notice that most of the mobile apps being created these days include animations in them. Why do suppose the use of animations is increasing in the creation of mobile apps these days? It is very simple, when you create an android app or an iPhone app and include animation in it then the chances of the app to retain the users for a longer period of time increases. Most users find themselves irritated when they are using a heavy mobile app and the loading time is long, if they have nothing to see on the screen then they are more likely to stop using the mobile app. What other reasons might be there for using in app animations?