Facebook has begun expanding the free voice calling feature on its Messenger app to Android users. Earlier this year, the company introduced free voice calling for iPhone users, letting them use the Messenger app to call other Facebook members. The app uses smartphones' Internet connections to make the call, either through a Wi-Fi network or over 3G or 4G networks. Now, three months after introducing the feature for iPhone users, Facebook started rolling it out to some U.S. Android users Thursday afternoon and says more users will get the feature throughout Friday. They don't need to update the Messenger app to use the free voice calling feature. :ranger: Once users get the feature, they can access it by tapping the circled "i" icon from within a conversation. After that, they can tap the "Free Call" button and the app will attempt to call the friend they are chatting with.