Facebook has started rolling out free VoIP calls over its Messenger app in the US. The service first launched in early January in Canada, and Facebook has confirmed to The Verge that the feature began rolling out to US users 16 January. Available on the iOS app, no update is required to access the service. To make a call, users need to open a conversation with a contact, tap the "i" button in the top-right corner, and tap Free Call. The recipient receives a push message notifying him of the call.
