Download Jio 4G Voice app: First, download and install jio 4g voice apk on your android mobile.After completion of installation open the app signup ith, you are jio unique sim card number.Now go to dialer section on your mobile and enter the number which is you want to connect. Now it is going to connect to the other number wait it will take only a few milliseconds to connect.
Now you can use this app as jio 4g free voice calling android app.This jio4gvoice app is working with voLTE signal so this signal is very much better than 2G/3G signal.
Through JioFi ( Reliance Modem) you can also use LTE features. This is not just for only this is also available for Rich Communication Services (RCS) in India.