To recall, the company had rolled out voice calling feature to its users in phases last year. The feature was first rolled out to WhatsApp users on Android followed by iOS, BlackBerry, and Windows Phone.

The voice call feature on Whatsapp is free and non-chargeable. The consumers use internet data to place the call. Although, the data used is charged according to the internet pack. The instant messaging service back in February had claimed that one billion people used WhatsApp.

"For more than a year, people have used WhatsApp Calling to talk with friends and family around the world. It's a great way to stay in touch, especially when connecting with people in other countries, or when messages alone won't do. Today, more than 100 million voice calls are made every day on WhatsApp - that's over 1,100 calls a second," WhatsApp said in a blog post.