How to add an icon to an android contact that link to my application

Question

I want to add an icon to a specific contact on it _ID and associate the action of this icon with my application. I need this icon when a user opens contacts and selects this user for viewing, here I want to put myicon in the "Call cell", for example, whatsapp icon for registered contacts

Answer 1

check out the link below for a detailed explanation with an example of writing a synchronization provider