Please Note* For good voice quality, need a good internet speed at both ends while using these.
1: Skype:
This app lets you do text messaging, voice and video chat. Skype to Skype is free.
2: Viber:
With the help of this app, user can do text messaging and voice calls free from viber to viber user. You don't require to register a separate user name for this app. After you have installed the Viber app, it syncs your contact list, automatically detecting which contacts area already using Viber.
3: Google+ Hangouts:
It lets you make free video calls that can be one-on-one.
4: Fring:
It enables you to make free calls. The group calling feature helps you to talk simultaneously with up to 4 users.
5: Nimbuzz:
It lets you send free messages and call other Nimbuzz users.
