wifi calling using csipsimple or other

[tangerine3]

I have a motorola razzr M and am going on vacation out of the U.S. I have heard I can make free calls if im connected to a wifi spot. Do I have to join a wifi calling service like google voice or skype to use the app csipsimple? Or can it be used on its own.

What I want to do is have a U.S. phone number and call from Trinidad/Tobago back to the U.S. and have ppl be able to call my cell phone from a landline or mobile phone to me while i'm down there, would I have a U.S. number so that they would have no charges . . . this is all very confusing to me. Thank you.

 

[pizza_pablo]

Viber : I recently read that this is the way to go.

 

[tangerine3]

this app link does not mention anything about people being able to call me for free while i'm out of the U.S.?

Any more suggestions on if I need to join a wifi calling service in addition to installing the csipsimple app?

 

[pizza_pablo]

this app link does not mention anything about people being able to call me for free while i'm out of the U.S.?

Any more suggestions on if I need to join a wifi calling service in addition to installing the csipsimple app?

I read, in an android forum, that is what this app is for.