Pocket-lint has been given a heads-up that UK iPhone owners will get voice calling and voice message functionality on their Facebook Messenger apps at some point today (25 March).
The features have been in test in the US and Canada for a couple of months, and Facebook is now ready to roll out the service to other regions.
Technically it will still be in test, so there may be glitches or bugs to iron out, but often these don't present themselves until software is in wider use.
Essentially, it allows users to make free calls to their Facebook contacts over Wi-Fi and, as it doesn't use Skype as the client, it works through Facebook all the way. Additionally, 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.
Facebook Messenger for iPhone is available as a free download on iTunes. It is also available on Android and BlackBerry but we're currently waiting to see if the voice calling and messaging update will be coming to those devices too.
Update: The feature is now available through the Facebook Messenger app. In our test it works well, with end call, mute call, mute microphone, and a slider to return to the app, buttons available.