Internet telephony company Viber has officially launched its Viber Out calling service which allows its 200 million-plus registered users to make low-cost calls to mobile and landline phones worldwide from within its mobile apps.

The service — which was first opened in the Philippines last month in the aftermath of a devastating typhoon — is available for all users of Android and iOS smartphones and the desktop app. Viber says it will roll out to Windows Phone customers soon.

Much like Skype’s own calling service, Viber customers can purchase credit via in-app purchases from the iOS or Android apps, or by using a credit card on the desktop client. The company touts its prices as being “significantly” lower than the competition — rates vary from country-to-country and whether you call a mobile or landline.

Viber Skype top73 730x584 Viber introduces Viber Out international calling feature, touts cheaper prices than Skype

There are plenty of VoIP calling services out there — Hong Kong-based Maaii being another — but, aside from messaging app features, Viber has a couple of other nice touches. It attaches itself to your phone number so the person you are calling will see your number flash up before they receive your call, it also hooks into your device’s address book to make searching for numbers a cinch.

“Viber Out gives our millions of users a new way to use Viber and ensures that they can reach any contact at any time,” said Talmon Marco, CEO of Viber. “We will continue to improve Viber Out, keeping our users connected at the most affordable rates possible.”

The feature is the second monetization stream that Viber has launched in recent months. Back in October it introduced paid-for stickers, but low-cost international calls may prove to be a bigger money spinner.

As a company founded before smartphone adoption became mainstream, Skype is still to translate the success of its desktop service to mobile and the launch of Viber Out will put additional pressure on the Microsoft-owned service, although Viber lacks the vast distribution that Skype enjoys.

In addition, the new feature also gives Viber clearer differentiation from WhatsApp, Line, WeChat and other messaging apps that compete with it for attention on mobile.

Image via watcharakun / Shutterstock