Big update for iOS also includes animated gif support and audio ducking
The iOS Hangouts app just got a major update that enables voice calling. If you're a Google Voice user, outgoing Hangouts calls will use your Google Voice number. Incoming calls to that number can be answered from the Hangouts app. Yes, iOS got this update before Android did. Yes, it's a direct shot at FaceTime Audio. And yes, it's very important to all of us as Android users.
Unlike the aforementioned FaceTime Audio, Hangouts is cross-platform. That means people using all the popular operating systems, both on the desktop and mobile, can communicate with each other. This is what Google does. This is what Google is good at.
Having Hangouts audio calling on iOS only is not how Google works. It will be coming to Android in the near future. It will probably be part of a much bigger update to Hangouts for Android devices. And we will cover the shit out of it. In the meantime, we're glad iOS users can give this a try, and hopefully when the update for Android and Chrome does come, all the kinks will be worked out and we can all call each other and do some sort of harmonious stuff.
If you have an iPhone, go update. And be thankful that Google loves you.
Source: +Vic Gundotra