WhatsApp is set to roll out the much-awaited internet calling after testing it with select users.
Earlier yesterday, a number of users of WhatsApp's Android app got the voice calling feature activated with a call from users who had the service turned on, The Times of India reported. It added, this meant that initial testers had been able to extend it to their friends who in turn got other WhatsApp users to join the club.
The invite system, though was not working for all users as WhatsApp might have set a limit to the number of users one could invite or was only allowing a limited set of users at this time to test its networks.
The feature was not available yet on the iPhone although WhatsApp's recent iOS update had introduced a calling button within the chat window. The feature also was not working on Windows Phone handsets.
On activation, WhatsApp's user interface changes to display separate screens for dialing a voice call to WhatsApp contacts, call logs and ongoing calls.
The chat window also displayed a calling button (represented by a phone icon). The active call screen also showed buttons for turning on the loudspeaker, switching to the chat window and for muting the call.
Meanwhile, India Today said that though the calling feature was available in several other instant messaging apps, with nearly 600 million users WhatsApp was in pole position to change the telecom industry with this feature.
Calling is supported on WhatsApp version 2.11.528 and currently, it was not clear if Android Lollipop was required for the feature or not, the report said.
Earlier, when WhatsApp was testing this feature on a limited basis, it worked only on Android phones running the Lollipop.
The WhatsApp calling feature added a new tab called calls into the app window, under which call history would be stored.
The feature also added a call icon on top of a chat window. Like with other messaging apps, for calls made using WhatsApp, users would be charged only for the data consumption.
They would not have to pay for "call charges" that they had to pay for the regular calls.