How To: Facebook's Messenger App Now Lets U.S. iPhone Users Make Free Phone Calls

If you use Facebook's Messenger app on your iPhone, your cell phone bill might just get a little cheaper. After recently adding voice chats to Messenger, the company just rolled out its new Free Call feature on the latest version of the iOS app, which allows users to make calls over Wi-Fi or a cellular data connection.

The feature only works between two people who are both using the latest version of Messenger and is not yet available on the Android app. Facebook says it "will be rolling out over the next few weeks," so you may not see it immediately.

The biggest catch is that in order to call someone, they have to not only be signed into Messenger, but also have shared a mobile number with Facebook. Calls placed over a 4G or LTE connection will still eat up your data, but if you use Wi-Fi it's completely free.

There aren't many details on the iTunes Store yet, but Engadget tested it out and found that the call quality is about as good as a landline. The most common criticism so far is that there's no easy way to tell who you can call—you have to view a friend's contact information and see if the Free Call button is greyed out or not.

If you're someone who has a lot of friends who use the app, this could eventually be a good way to cut down on your phone bill (especially once it's added to the Android version).

Will you use Facebook's Free Call feature? If you've already tried it out, let us know what you think in the comments below.