Atlassian is to acquire Trello, a popular team productivity app for $425 million.

Atlassian, which itself makes the collaboration software tools Jira and HipChat, will maintain the freemium model of Trello, which will be acquired for $360m in cash and $65m in restricted shares and options.

Trello was originally released by Fog Creek Software in 2011 before being spun out in 2014 and has roughly 19 million users.

For Atlassian, the deal boosts its portfolio and hands the company 19 million more users, if they decide to stay. Mike Cannon-Brookes, CEO, said: “Trello will become an important part of the Atlassian portfolio, offering a fun new way for teams to organize the often messy range of information that feeds into great teamwork.”

Michael Pryor, CEO, Trello, told its users on the company’s blog that the company will be able to leverage Atlassian’s investments in R&D to help to enhance the product.

“Our team will be able to focus on improving the core experience of Trello for all users. We are certain that Atlassian understands the unique and novel reasons why Trello is so successful and well-loved,” said Pryor.

Software company Atlassian, was founded in Australia 15 years ago and has been on an expansion mission in the past few years. Last year it acquired StatusPage for an undisclosed amount and it had a successful IPO in December 2015.

The collaboration tool market is certainly a competitive one with the likes of Box, Dropbox, Jive and Slack some of the big names in the market, while the likes of Facebook has entered the market with its Workplace offering.

Acquisitions like this not only help to boost user base, and will hopefully make it easier for Trello users to start using Atlassian’s products, they also boost innovation with the addition of new tools, something that’s likely to keep customers with the product.