FaceTime Audio & Video calling has been around quite a while on the iPhone and then the Mac. Apple has improved it some over the years. I use it on occasion to talk to family around the country, but I am by no means a heavy FaceTime user. If you use FaceTime or would like to use it more often, then check out this article which explains how to use FaceTime on the iPhone and Mac. It even explains how to turn an Audio Call into a FaceTime Call.