what is the best application for internet calls?

Viber is the best PC to PC and app to app free internet phone calls which is available today.
Viber works with many different devices. The mobile application can be installed for iOS and Android users.

WhatsApp is the most popular messaging platform it has also introduced voice and video call features which works best in 2g network aswell..

Skype is the best one with better phone quality when compared to all. For something other than skype, you can go for wechat, viber or whats app..

Google launched a latest video calling app named Google Duo which supports internet and regular voice calls as well.

Hangouts are trending nowadays. You can give this a try..

Text now is an app that can send and receive free phone calls with other users. It is good to use and one of the best software