Facebook’s Messenger app now has 1.2 billion monthly active users since first launching in August 2011.
Messenger was spun-off from the main Facebook app to allow users to focus on exclusively messaging their contacts.
Some users complained that it requires them to download two apps, though the Facebook app does not need to be installed to use Messenger.
“I keep on hearing powerful stories about how our product is becoming a more important part of your daily lives,” wrote Facebook’s Head of Messenger David Marcus on his announcement post for the milestone.
“So from all of us here at Messenger, a heartfelt thank you to all of you for giving us a chance to build something good and more meaningful for you.”
Further, Facebook Messenger has rolled out a host of new features including the ability to send or receive money between groups on people on the app.