Slack, the workplace communication app that began as a way for gamers to communicate, now has 10 million daily active users, the company reported today. That’s up from 4 million daily active users in 2016 and 8 million last year.

Teams using Slack have made hundreds of thousands of custom Slack apps, and there’s more than 1,500 ways to automate workplace tasks in the Slack App Directory. The directory includes automated bots and apps from third-party developers as well as integrations from SaaS products like Salesforce, Jira, and HubSpot as well as cloud providers like Google Cloud and Box.

The boost in daily active users also follows Slack’s acquisition of competitors HipChat and Stride from Atlassian and absorption of users from both workplace apps.

Not long after the acquisition, in its haste to keep up with fast-growing Microsoft Teams, Slack raised a $427 million funding round to bring its valuation to $7.1 billion.

Slack also announced today that it has 85,000 paid customers, up more than 50 percent over the past year. Slack said it has a total of 3 million paid users last year in another milestone announcement. VentureBeat has pinged Slack for additional details.

Along with companies like Lyft, Uber, and Pinterest, Slack could become a publicly traded company this year.

Though Microsoft Teams is just over two years old, the team communication app initially for Microsoft Office 365 users is currently used by more than 329,000 organizations, up from 200,000 in early 2018, far ahead of competitors like Workplace by Facebook, which is currently used by about 30,000 organizations.

A free version of Microsoft Teams was introduced in July 2018 shortly before the HipChat-Stride acquisition, and last week Microsoft introduced Team Rooms, a rebranded version of Skype Room Systems, for conference room control within Teams.