While Facebook
doesn't charge you to use the new feature, it does eat up megabytes from your
data plan unless you're connected to WiFi. The social network started testing
this feature over WiFi and cellular data for Messenger users in Canada earlier this month. It's not currently available for Android or BlackBerry
users.
To use the
feature, both you and the friend you want to call must have the Facebook
Messenger for iPhone app installed.
To place a call,
open the Messenger app and search for a friend. Tap the Info button in the
top-right of your friend's conversation page to bring up the screen shown at
left. If your friend is using the Messenger app, the "Free Call"
button will appear in bold; if not, it will be greyed out.
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