When I am overseas I use Skype on the computer if my SO is at work. I have a year subscription so I can call phones and cells. If I call my daughter I use facetime as she is never on Skype. My driver in the UAE we use WhatApp. They much prefer that than a voice call. I have never used Imessage overseas. Is that free to use internationally? I always use a local sim as I am always in country for at least a week.