• by Erik Sass , Staff Writer @eriksass1, April 3, 2015

With Internet-based video services already threatening cable operators, another front in the war on exorbitant fees emerged this week with WhatsApp’s launch of a voice-calling feature for its Android app. This feature allows mobile device users with Internet access on their smartphones to make calls without having to use their allotted minutes, courtesy of WhatsApp -- which previously allowed users to skirt text limits.

WhatsApp tested the new voice-calling feature in beta with a select group of users last month, and is now in the process of rolling it out globally. It requires at least an Android 2.1 operating system or more recent version, and is currently only available for smartphones, not tablets. The new version of the app will be available at Google Play as well as the WhatsApp Web site.

The free voice-calling feature comes two years after the free voice messaging service introduced by WhatsApp in 2013.

WhatsApp, acquired by Facebook last year, has a relatively low profile in the U.S., but is hugely popular in a number of other countries. For example, according to data published by Global Web Index last year, 78% of South African mobile device owners have used the messaging app, along with 70% of Spanish mobile owners, 69% of Indians, 67% of Mexicans, 62% of Italians, 57% of Germans, and 56% of Brazilians.

In other words, a very sizable chunk of the world’s population just got access to free, unlimited voice calls -- although there’s an important caveat, as data charges still apply, of course. Whether it makes economic sense to save teleco minutes by incurring data charges will depend on individual users and their mobile contracts. But currently a five-minute call on WhatsApp uses about one megabyte of 3G data, which would cost about one cent on Sprint’s U.S. basic three-gigabyte data plan. That definitely seems like a plausible competitor to telecos offering limited minutes and charging fees when you go over.