Microsoft's purchase of Wunderlist creator 6Wunderkinder is official. Today the company published a blog post confirming the deal, which The Wall Street Journal reported yesterday. "The addition of Wunderlist to the Microsoft product portfolio fits squarely with our ambition to reinvent productivity for a mobile-first, cloud-first world," Microsoft's Eran Megiddo wrote. "It further demonstrates Microsoft’s commitment to delivering market leading mobile apps across the platforms and devices our customers use — for mail, calendaring, messaging, notes and now tasks." The acquisition price, rumored to be between $100 million and $200 million, isn't being disclosed.

Much like Sunrise, it sounds like Wunderlist will continue operating as normal for the foreseeable future, with Microsoft ultimately planning a deeper integration with its own apps somewhere down the line.

Customers can expect the app to remain free in all of its existing markets. There will be no price changes for Wunderlist Pro or Wunderlist for Business customers and the service will continue to support a wide range of third-party apps and integrated services.

Wunderlist founder and CEO Christian Reber says the deal opens up new possibilities for what's already a very popular to-do list app. "Joining Microsoft gives us access to a massive wealth of expertise, technology and people that a small company like us could only dream of amassing on its own," he wrote. "I will continue to lead the team and product strategy, because that’s what I love the most: building great products that help individuals and businesses get stuff done in the simplest and most intuitive way possible."