Facebook has brought its free voice calling feature within the Facebook Messenger app over to Android users in the US, after it saw its Android debut in the UK last month.

Facebook has begun pushing the feature to users over its servers, leaving no need to update the application from Google Play.

In our testing, the free calling feature works great, allowing you to call any of your friends with a supported app installed. The calls don't eat into your precious cellular minutes - just your data plan if not on Wi-Fi. There are other solutions such as Skype and Vonage, but Facebook has all of your friends in one convenient place, so we seeing it being the best.

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. If your contact doesn't have Facebook Messenger open or lurking in the background of their device, you can leave them a voice message to pick up later.

If you have Facebook Messenger or Home's Chat Heads enabled, you'll have to move the conversation over to the Messenger app before initiating a call.

It’s worth noting, the feature is cross-platform, available for both Android and iPhone users in both the US, UK, and 22 other countries.