How to mimic the listView stickey-items like on Lollipop's contacts app?

Question

Background

Google has recently published a new version of Android, which has a contact app that look like this :

Answer 1

I answering so late, but I hope my answer will help to someone. I also had such a task. I have been looking for answers and examples of sticky header, but for recyclerView. I found the best and simplest solution in the article "Sticky Header For RecyclerView" of Saber Solooki.

Based on this example, I made my contact module for my application, it is very simple.