BlackBerry has shut down its once-popular instant messaging service known as BlackBerry Messenger, or BBM.

According to the website , BBM users were logged out of instant messaging platforms and left with a goodbye message reading “BBM Consumer has signed off.â€

“We are proud of what we have built to date,†Emtek, the company that in 2016 took over the operation of the BBM app, wrote in a blog post announcing the shutdown. “The technology industry however, is very fluid, and in spite of our substantial efforts, users have moved on to other platforms, while new users proved difficult to sign on.â€

BBM, which arrived on mobile devices in 2005, was one of the first free instant messaging platforms and one of the world’s most popular mobile social networks. A predecessor to the Facebook-owned WhatsApp and Apple’s iMessage, it was also one of the first instant messaging services to feature read receipts.

In 2012, the word “BBM,†which could be used as both a noun and a verb, was added to the Collins English dictionary.

The Waterloo, Ont.-based tech firm has in recent years shifted its focus from handsets as it reinvents itself into a software development business.

It says that it will continue to offer BBMe, a messaging service that is similar to its predecessor. But while the service will only be free for the first year, users will have to pay for a subscription after that. as the tech company continues to shift its focus from handsets to its software development business.