Facebook’s (NASDAQ:FB) WhatsApp voice calling is coming to Apple’s (NASDAQ:AAPL) iOS devices and Microsoft’s (NASDAQ:MSFT) Windows Phone devices.

It’s unknown exactly when WhatsApp voice calling will comes to iOS and Windows Phone devices. There also hasn’t been any news of if it will ever comes to BlackBerry (NASDAQ:BBRY) devices. As it stands now, users can only activate the feature if called by someone who has access to it, reports The Hoops News.

WhatsApp voice calling was announced for devices running on Google’s (NASDAQ:GOOG,NASDAQ:GOOGL) Android operating system in March. The expansion of voice calling to more devices could make the service a strong rival to Microsoft’s Skype, The Hoop News notes.

In the last two months, there have been 10 beta versions of WhatsApp voice calling that have been released. It’s likely that the service will be expanded to more devices before the end of 2015, reports The Fuse Joplin.

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