I would like to find out more about using T-Mobile in Brazil.

In preparation for my family's upcoming trip, I have acquired 3 SIMs during a promotion for 1 cent each, and plan to sign up for the 3 phone family Simple Choice Plan for $90. This plan includes "Unlimited international data & text in 120+ countries and destinations PLUS unlimited international texting from the U.S. to virtually anywhere*" (Brazil is in the list of 120 countries).

This I don't understand..."Calls over Wi-Fi are $.20/min (no charge for Wi-Fi calls to U.S.)". tmo customer service explained to me that calls made/received while in Brazil are 20 cents/minute.

In the included data roaming, can apps like skype, vtok, whatsapp, lime, etc... be used to make/receive calls?

Thanks!