Facebook has been testing free calling over Wi-Fi and cellular data, and the service has been available to iPhone users in Canada for some time. Now the service has reached iPhone users in the US as well. It is available through the Facebook messaging app.
As of now, the service is restricted to the US and to iPhone users and there is no information on when the service will hit Android or Windows Phone devices in the US or when the service will be available globally.
Making a voice call to another Facebook user is quite simple. Users need to open a conversation with a friend, tap the "i" button in the top-right corner, and hit the Free Call button. The call recipient will then get a notification that a Facebook user is trying to call them.
The service is a very nice addition to the messaging app. This means that you can make free calls without making your cellular bill go up. If you have a great data plan, you can make calls via cellular data and save your phone bill.
In the past, Facebook tied up with Skype to allow video chat on the browser version of Facebook. There has been no translation of the service to the mobile version of Facebook, which is a bummer. It also makes us wonder if the voice-calling feature is limited to the messaging app or will it translate to the browser version of Facebook as well.
Facebook was testing VoIP calling and voce messaging via its messaging app in January. You can read the details of that story here. Facebook yesterday announced the new Graph Search engine on its social networking website, making search results more relevant to you on a social scale. Data accumulated from user profiles over the years make results closer to you and your friend's circle. You can read our in-depth take on the service here.
Source: The Verge