Android check contacts if they are registered in an app

Question

I need your help. I\'m developing an app which needs user to register account like Viber. What I want to include is to check if one of my contacts has already an account in

Answer 1

If you are going to develop a similar app like viber.I think you can get the complete contact by susing contactsprovider and display it in a listview on clicking on a row in this listview you can pass it to your server in the server set phone number as unique field,so that you can check for match.