It's a Sample App for showing about How RecyclerView/View Binding work's, Both RecyclerView/View Binding is Part of Android Jetpack.
View binding is a feature that allows you to more easily write code that interacts with views. Once view binding is enabled in a module, it generates a binding class for each XML layout file present in that module. An instance of a binding class contains direct references to all views that have an ID in the corresponding layout. In most cases, view binding replaces findViewById.
RecyclerView makes it easy to efficiently display large sets of data. You supply the data and define how each item looks, and the RecyclerView library dynamically creates the elements when they're needed.
As the name implies, RecyclerView recycles those individual elements. When an item scrolls off the screen, RecyclerView doesn't destroy its view. Instead, RecyclerView reuses the view for new items that have scrolled onscreen. This reuse vastly improves performance, improving your app's responsiveness and reducing power consumption.
Note: Besides being the name of the class, RecyclerView is also the name of the library. In this page, RecyclerView in code font always means the class in the RecyclerView library.
https://developer.android.com/topic/libraries/view-binding
