WhatsApp tests internet voice calls

WhatsApp, the Facebook-owned mobile messaging app, which is adding voice calls, has started beta testing internet calls with a number of users.

The app's new feature changed the app's interface in minor ways, including a separate tab that listed voice call activity, according to BGR India. It worked on 3G and EDGE networks - that were cheaper and tended to be more widespread in emerging markets such as India and China.

With its functional and ad-free interface, WhatsApp had attracted a massive user base of over 700 million monthly active users worldwide. And though the market for apps of its kind for the developing world was becoming increasingly crowded, it had secured a spot for itself as a frontrunner in the competition.

If it grabs some of the market share from its challengers, especially those with a strong focus on voice calling, like Viber and Skype, it would be able to further consolidate its position.

Meanwhile, according to commentators, such apps and services would continue to be on the radar of the giants of the tech world, as they looked to leverage new opportunities. That was the reason for Facebook's acquisition of WhatsApp.

Google also reportedly wanted to build its own mobile messaging competitor.

Also only last month, Twitter acquired a Bangalore-based mobile marketing platform called Zipdial to secure a foothold in the Indian market.

It was not clear though, when the voice call feature might be rolled out more widely or when the app's iPhone users would be able to use it, Mashable reported.

The advantage of internet-based calling, was that users could make a phone call, provided they have a Wi-Fi or 3G connection, without using up often-pricey carrier minutes.

The announcement of the feature had come during Mobile World Congress last year from WhatsApp CEO Jan Koum.

According to the company, it was not testing the feature with iPhone users yet, but call buttons had appeared in the iOS version of the app, though they redirected to the iPhone's native phone dialer.