The new feature is pretty similar to voice calling found in other messaging apps, like Viber and WebChat. With the new update, users will be able to make calls to friends for free provided they have a WiFi connection. A phone icon now appears when you view your contacts in Messenger. Simply tap the icon to initiate a phone call. Both participants in the phone call need to have a WiFi connection or a data connection.
This update came a mere weeks after pics of voice calling on WhatsApp started popping up on the internet. That feature had been rumored to be in the works for some time before the pictures leaked online. What's really interesting is that the leaked screenshots of WhatsApp's in-call screen and the in-call screen for Facebook Messenger are practically identical to each other and to the in-call screen of iOS 7. The only difference is the in-call screen for the Android app.
The messaging app for Facebook mobile is definitely a handy little tool. It allows users to send messages to other Facebook users without having to be in the actual Facebook app itself. In addition to that, the app also allows users to pop out chat heads for quick access to any ongoing conversations. The chat heads can be a little distracting, though the ability to literally move the chat head around anywhere on the screen (like any other app) gives you complete control over where you want it.
I wonder, however, how users will take to the calling feature for messaging. I personally use the messaging app all the time, though I don't see much use for the phone calling app. If I want to call someone I'll just use my phone like normal. I guess this app could be considered useful if you wanted to or needed to call someone who you are friends with on Facebook but don't have their number. It could also be a good way to call people without actually exchanging numbers, if you ever needed to be in a situation like that.
You can grab this latest version of Facebook's Messaging app on the Google Play store and the Apple App store for iOS and Android users. Users of the app on Windows Phone devices are still waiting on the update.