YouTube has been testing a feature in select markets that allows the platform to become a kind of mobile messenger. The feature, which began testing in mid-2016, lets users avail themselves of a new tab in the mobile app to send videos to their friends and chat. After a soft rollout to users in Canada at the beginning of 2017, YouTube later launched the new feature in parts of Latin America. The global rollout  this week, but will take a few days to appear on all users’ phones. YouTube also tweaked the user interface in several ways.

TechCrunch reports that the changes include “the way the chat interface appears to users.” YouTube also “made the video stick to the top of the chat when scrolling down,” and “introduced the ability to allow replying and chatting while users are watching a video, which gives the feature more of a real-time feel.”

YouTube users “can also reply to videos they receive with other videos, or even a heart” and “group sharing with up to 30 people is supported.” The app that was tested, dubbed YouTube Uptime, however, included emoji responses and co-viewing, two features that were not carried over to the newly rolled out app, but “YouTube says that more improvements will be rolled out in time.”

The new ability to share video and chat about it is YouTube’s effort to “transition some of the social activity that takes place around videos … back into YouTube instead of other messaging apps.” But, notes TechCrunch, “it’s unclear if it will be successful in that regard” because “people’s preferred mobile messengers already have their established social graphs, and YouTube is having to build its social network of people’s friends and family from scratch.”

The feature allows users to find friends from their phones’ Address Books, but “there’s currently no way to block requests from those you don’t know.” Users can, however, deny the requests, “but for public figures or those whose name or contact information is more freely available, this can be a problem.” The TechCrunch reviewer tested out the feature and “had a slew of incoming requests from strangers.”