Facebook has updated its iOS application with several features and bug fixes. Most notably, US and Canada users can now make free voice calls over Wi-Fi and 3G/4G to Facebook friends.

The calling feature first debuted in Facebook Messenger earlier this year and allows Facebook users to call each other using no minutes - just their data plan if not on Wi-Fi.

Users can access the feature in the message inbox on the app. Initiating a call is easy by just tapping the "i" button in the top-right corner of chat with another user. The user on the other end will receive a push notification to accept or refuse the call, as long as they have the updated version as well.

Additionally, Facebook has packaged new and improved buttons for liking, commenting, and sharing posts in the update. There is also a new share button for easy reposting.

The free call feature is useful, as it allows users to save precious minutes. Since 650 million users are now using the mobile version of Facebook, we bet more than a few of your friends will adopt the feature.

Verison 5.5 of Facebook for iOS is available now from the App Store. No word on when the free calling feature will land in the UK.