WhatsApp's plans to launch voice calling feature has been leaked several times in the past, and today, the feature has started appearing for some users. A Reddit user pradnesh07, who received the feature on his Android smartphone, has mentioned that the feature got activated when his friend (who already has the feature enabled) called him through WhatsApp.
The Reddit user went on to say that he tried to call as many friends as possible to help his friends in activating the calling feature on WhatsApp, but it was more of a hit-and-miss situation. If you are wondering about when WhatsApp has updated the app, this feature is available only when you have downloaded the latest APK from WhatsApp's official website, and not from Google Play Store.
Earlier this month, WhatsApp launched WhatsApp Web, which you can use from your web browser, bringing WhatsApp to desktop's reach. Its competitor Hike has also launched voice calling feature earlier this week.