FaceTime

FaceTime is video conferencing software created by Apple Inc. for use on the iPhone, iPad and computers running Mac OS X. To call people, you type in their email address or phone number. FaceTime supports high definition video.
FaceTime was first announced by Steve Jobs on 7 June 2010 at Apple's Worldwide Developers Conference. Video is sent using H.264 and audio is compressed with AAC. With Facetime, people can talk to people that are far away face to face.
FaceTime Audio.
An audio-version of FaceTime was announced during Apple's annual keynote speech on June 10, 2013, and later released on September 18, 2013. The service provides high-quality audio. Initially, FaceTime audio was only usable on a Wi-Fi network, but since has been updated to work over 3G and LTE data connections. Currently, FaceTime audio is only available between Apple devices.