Facebook CEO Mark Zuckerberg has framed the messaging tool merger as an added convenience for users. (Josh Edelson/AFP/Getty Images)

Facebook’s plan to combine the messaging tools of all its apps may already be underway, according to an independent researcher who spotted a new test feature in the platform’s namesake app.

Jane Manchun Wong, who’s known for uncovering unreleased features and vulnerabilities in software, has discovered a tool that she says would allow users to message one another without leaving the Facebook app for Messenger, as they must do now.

Facebook removed the ability to chat in its app in 2014, which compelled users to install Messenger, the standalone chat app it launched in 2011. At the time, many users questioned why they needed two apps. The move also highlighted Facebook’s strategy to build a dominant position in mobile messaging. That same year, Facebook acquired WhatsApp for $19 billion.

In an interview Friday with The Washington Post, Wong speculated that, “this is part of the execution of Facebook’s recent new strategy of integrating messaging platforms of their products so they can interoperate better with one another.”

The plan, unveiled last month by chief executive Mark Zuckerberg, would merge the company’s messaging services, allowing Facebook, Instagram, WhatsApp and Messenger users to communicate seamlessly, without having to switch to apps.

“We want to give people a choice so they can reach their friends across these networks from whichever app they prefer,” Zuckerberg said at the time. He also said the feature would be opt-in, allowing people to keep the accounts separate if they preferred.

Though Zuckerberg framed the messaging tool merger as an added convenience for users, European officials have criticized the plan on possible antitrust concerns.

Just this week, Germany’s justice minister Katarina Barley said in a statement that centralizing the messaging functions raises “very significant cartel law and data protection law questions.” And, she added, “Facebook must not become a gigantic, self-contained communication space that concentrates yet more market and data power.”

The plan also raises questions for regulators. Part of Zuckerberg’s reorientation of Facebook is moving the service away from the public broadcasting of social media and toward private, encrypted communications. But many governments oppose the widespread use of encryption, which shields the content of messages from outsiders, including law enforcement.

And though secured communication may help protect consumer privacy, it may stymie Facebook’s ability to curb misinformation and remove malicious actors from its platforms, since doing so requires reading what people are posting.

For now, the unreleased chat feature is limited. Wong said it supports basic messaging functions — reading and sending messages as well as GIFs. But to send message reactions, call someone or send photos, the Messenger app would still be required, she said. Wong said the limited nature of the chat feature indicates it’s not meant to replace Messenger, but to allow Facebook’s suite of apps to operate together. The feature could also be in early development, she said.

Facebook did not immediately respond to a request for comment.

The company estimates that more than 2 billion people, on average, use Facebook, Instagram, WhatsApp or Messenger every day.

If the response to Wong’s findings is any indication, there’s appetite for reunification.

“Finally! Forceful downloads of additional apps is just wrong” @fafles posted on Twitter.