Apple having very frequent updates OS X Mavericks 10.9.1 was just released and now seeded OS X Mavericks 10.9.2 Beta to developers. Till now only iOS 7 devices had access to FaceTime Audio calls, now you are going to get it on OS X as well. Apple is going to make iOS and OS X communication system very strong with FaceTime, FaceTime Audio and Messages.
In this first OS X 10.9.2 beta Apple includes FaceTime audio, VOIP (Voice over internet protocol) like originally in iOS 7. Apple asks testers to focus on Mail, Messages, VPN, Graphics Drivers and VoiceOver. Register developers can see the update available in Mac App Store.
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