Which is best app free calling without internet connection?

[Farman7]

Is there any app which provides free calling where the receiver doesn't need any app or internet connection to receive calls?

 

[UJ95x]

You need an Internet connection to make calls over anything that isn't the built in phone app. Google Voice and WhatsApp let you make phone calls but still need data

 

[Crashdamage]

Google Hangouts used with the Hangouts Dialer will make free calls via VOIP to any phone in the U.S. The receiver doesn't need any app or data., but you must have an internet connection to place the call.

Google Voice does not use a data connection. Calls are made over your regular cellphone connection.

Android since v1.0. Linux since 2001