Facebook has announced a group calling feature for its Messenger app in the next stage in its plans to become an all-round communications platform rather than simply a social network.

Users of Messenger can press the phone icon within any group chat to initiate a group call, David Marcus VP of Messaging Products at Facebook wrote in a post on the site.

They can then manage which participants join the call in the following screen.

People who have the latest version of Messenger on their phones will see the icon appear in group conversations within the next 24 hours.

Currently Hike, FaceTime and Skype provide group calling, although Facebook-owned WhatsApp currently doesn’t.

Of its two chat apps, Facebook’s Messenger service is the one that has been repurposed for the business market, with the messaging service originally built inside of the core Facebook at Work app.

Later it was unbundled and offered as Work Chat.

Assuming that the group calling feature is rolled out to Work Chat as well, the move is one more step to making Facebook’s offering a serious competitor to other unified communications products.

Unified communications, a category of technology which has been showcased this week at UC Expo, provides businesses with a full range of integrated communication channels, with the ability to switch from chat to call to video without changing apps.

Showing that this might be a target area of Facebook, Julien Cordorniou, Director of Platform Partnerships at Facebook at Work, spoke at the conference, discussing connecting the workplace and mobile-first technologies.

Currently Facebook can do some but all of these things. The chat and share capabilities are a given, with calling and group calling now available.

Messenger does feature video calling but users can only call one friend at a time, unlike with platforms like Skype. Eventually, all chat apps integrating video calling will be expected to provide not just group calls but group calls on mobile.

In addition, an increasing theme in unified communications is the ability to collaborate with co-workers on documents.

Since Facebook doesn’t offer business software such as CRM itself, this requires integration with other companies’ products.

There are signs that Facebook is moving in this direction. A recent theme at Facebook’s F8 Conference was Facebook opening the Messenger service to developers with the launch of the Messenger Platform, which will allow developers and businesses to use the platform to interact with customers.

It launched the Beta version of the platform with bots as well as the Send/Receive API.

One significant partnership saw Dropbox launching a new feature to make it easier to share photos, videos, and other files in Facebook Messenger.

When the user taps the More button in Messenger for iOS or Android, Dropbox will be available as a source. This means that if the Dropbox app is installed, users can directly share any file in their Dropbox without having to leave the Messenger app.

Showing how Messenger might be used in another important part of unified communications, in engaging with customers, Salesforce launched Salesforce for Messenger, which will allow retailers to embed a Messenger plugin on the checkout workflow on its website to allow customers to ask questions before making a purchase.