Facebook starts turning on free voice calls for iPhone users in the US

Earlier this month word got out that Facebook was trialing a free voice calling feature in Canada. We said that, if those tests went well, the company would expand to the US. Well, things must have gone swimmingly because, just two weeks later, American customers are starting to see the same feature turn up in the Messenger app. Just tap the "i" icon in the top right hand corner while...