First: Fill in Edittext email and password. If you don't have account, you press sign up and fill in you phone number. Else if you have account, you press sign in. Second: You can see all buddy use this app, this will discover your contact and compare on firebase. Additional, you can fill in phone number to call other device signed in this app.
- On devices using Android 6.0 above, you must set permission in app info.
- All devices must be sign in to call together.