A probable voice-calling support from WhatsApp was always on the cards, even if no one earlier spoke about it. And such an addition is only justified with other such IM providers also following suit. But since WhatsApp has been adapted by millions across the country, the wait for the functionality on the IM is massive.
Last Friday, several Android mobile users were able to use the voice calling feature on WhatsApp after receiving a call from a friend who already had the service activated. The feature, then, was not available to all the users, suggesting that WhatsApp is still testing it by rolling it out to a selected group of users.
According to a latest Android Police report, the calling feature was activated for selected users who could pass on the invitation to their friends by making a WhatsApp call. However, this invite-feature has since been disabled by WhatsApp.
Users who have already activated this feature can still make calls to their friends. However, you cannot activate the option for others since WhatsApp has disabled the invitation feature and was simply testing its servers to analyse its call functionality.
Previous to this, users with WhatsApp version 2.11.528 (from the Play Store) or 2.11.531 (from WhatsApp website) could see the caller icon on their app and make a call to their friends and pass on the invite. The invite dealt with getting a call from someone who already had the calling feature activated.
A Reddit user pradnesh07, got the feature activated on his phone. And according to the images posted, users who receive the voice-calling feature will notice an icon for it beside the Chats and Contacts tabs. The call interface is quite similar to a smartphone's contact directory, while the app keeps a record of recent WhatsApp calls as well.
So if you are one of the selected few who were chosen for the feature and activated it, but cannot use the voice-calling feature anymore, know that the earlier release from WhatsApp was sort of a dry-run. Like a demo that you get to play with before the final title launches.
There's absolutely no problem with your smartphone or the WhatsApp app installed on it. The company was just testing the feature and has now halted it to make notes and introduce further changes and fixes. The final build should arrive soon, allowing you to invite friends as well.