It lets buyers and sellers on the huge marketplace show status messages about a shop, make announcements, keep in touch with customers and offer customer service.
Owned by Shanghai-based online games and book publisher Shanda, Youni is a mobile commerce and messaging app that can be linked to a user's bank account to transfer small sums of money.
In the mobile space, Facebook is dealing with a whole other breed of competitor.
Snapchat added video calling earlier this year, while Whats App just made the feature available widely to the public last month.
The mobile version had 576 million monthly active users as of the end of 2014, an increase of 33 per cent over a year earlier.
Riding on the back on China’s mobile user base, it has remained a wildly popular platform for chatting, gaming and also shopping, though its growth is much slower than its stablemate We Chat.
The social network is clearly interested in capturing both consumers and, with the recent launch of its Work software, office employees who do a fair amount of telecommuting and video conferencing.
To that end, workplace chat app Slack beat Facebook to the punch, adding video chat just last week.
For the first six participants, the app will stream everyone’s camera feed to one another in a grid-like view.
While video chatting, the company stresses that Messenger’s other functions remain intact.
So you can still send texts, stickers, and other animations while video and audio are transmitting.
The addition of video chat follows an April update that first added group calling to Messenger.
Prior to that add-on, Facebook’s app was only capable of making one-on-one audio calls.