A recent update to WhatsApp for Android rolled out the much-awaited voice calling feature to more people. WhatsApp version 2.11.528, released on February 19, is reported to have given some users access to voice calling. These people could activate the feature for other WhatsApp users on Android simply by making a WhatsApp call to them.
WhatsApp hasn't made any official announcements regarding this feature and there's no mention of it in release notes on Google Play either. The voice calling feature rollout appears to have stopped soon after its release, according to a report.
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WhatsApp appears to be rolling out this feature in short phases with Android being the first platform to get it. WhatsApp for iPhone still doesn't have this feature even though a voice calling button appeared in the app some time ago.
After establishing itself as the world's most popular messaging app with over 700 million monthly active users, WhatsApp seems to be playing catch up by adding features available in competing messaging apps. Apart from voice calling, WhatsApp recently launched a Web version that works surprisingly well. Both these features have been available for some time with competing messaging apps such as iMessage (calling via FaceTime), Line, Viber, among others.
WhatsApp was acquired by Facebook last year. WhatsApp CEO Jan Koum had said that voice calling would be rolled out in Q1 2015. So far, the company appears to be sticking to that deadline. As of now there is no word on when the feature would be made available to non-Android users.