Facebook has unveiled that video calling feature on its Messenger app is now available globally, with the exception of a few countries where it is still working to improve the quality. So if you would like to try this new free calling service, try updating your iOS or Android app first and see if your country is one of those who have access to it.
"Quick update on video calling in Messenger: we’re happy to share we’ve now rolled out the capability globally, with the exception of a few countries we’re still working on improving quality for. So make sure you get the latest and greatest version for iOS and Android, give it a try, and as always… tell us how we can make it even better for you!" - David MarcusThe feature was first activated a few weeks ago in the US and some other 17 countries. But today's update it should be working on most countries, if not all, that have access to the messenger app.