App for free calling on android and Iphone using WiFI or Data

[sashadidi]

Hi I have used this app on my Iphone to my friend on a Iphone in Australia, its free if you use WiFI or $$ if you use data but works great, apparently works on android as well
now they are stuffed as its free as long as you have Wifi especially, just pop down to Maccas and make a call anywhere in the world once your contacts worldwide have this app.
http://viber.com/

[p38arover]

I have it on my iPhone but I don't have any contacts who also use it. :(

[Reads90]

Yeah good and really clear
I use it to call my brother in the uk