How to check if the number is on Airtel network?

Airtel has launched dialer addon for my-airtel app user. It is giving away 50 A2A mins free to dial using this dialer. Best part is user can know if the customer is on Airtel or not.

All Airtel no shows free call in front of them which means that the no is on Airtel network. check the screenshot below.

Hoping that Airtel launches free A2A calls for everyone once this dialer uses vowifi-volte to make calls when launched.

This dialer is in response to Jio4G call app which allows Vo-LTE calls. Not yet clear what this app aims to achieve? Hopefully Volte/Vowifi to be launched sooner on Airtel network also.