Android preview before showing the contents

Example photo of preview in Yelp

When I use some Android or IOS application or Web, I can see the preview of the content before it is loaded sometimes. I mean gray part of the view of list which has ripple effect sometimes. I think many applications are using that function similarly, so I wonder there is some built-in or 3rd party library of Android for that preview function. Or, it is developed by their own code. If it is their own code, how to implement that kinds of preview?