Research In Motion (RIM) is now letting its BlackBerry Messenger (BBM) customers make free voice calls via a Wi-Fi network. The company revealed on Wednesday the feature will be added to its BBM offering and is free to current users. BBM users are not charged per text sent.

“Users will be able to switch back and forth from a text chat to a voice call,” according to a report from The Associated Press. “A split-screen option will let them talk and text at the same time.”

The BBM voice option may be particularly popular in developing markets as the BlackBerry is touted as being highly competitive in such nations as South Africa, Nigeria and Indonesia. But it is less competitive in the United States, where it has rivals like Samsung – using the Android OS – and Apple’s iPhone.

In January, RIM will introduce the new BlackBerry 10 smartphone. The company has made much of its future rest with the success of BB10.

In other company news, despite the company’s challenges RIM recently revealed its number of subscribers is growing which due in part to BBM and its popularity in developing markets, The Wall Street Journal revealed. RIM has more than 60 million BBM users, compared to some 50 million in 2011.

"BBM is the quick, easy way to stay connected to the people that matter to you, and with today's announcement we're expanding the capabilities of the service for deeper social engagement and even greater collaboration, beginning with voice functionality," T.A. McCann, vice president of BBM and Social Communities at RIM, said in a company statement carried by TechZone360. "The new BBM Voice feature is for when you're travelling and you want to call home without worrying about phone charges. It's for when you have news you can't wait to share, for quickly explaining complicated details, and collaborating with colleagues. Whenever your ideas are too big for text, there's BBM Voice.”