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

To achieve something similar to the contact list of phone, This is the BEST solution I came across!

This will also work with the custom list as Images may need to be there with the name. Above solutions only have the list or array of String which may not everyone need!