Microsoft has acquired yet another popular app maker

Microsoft Corp. has agreed to acquire 6Wunderkinder GmbH, a Berlin-based startup behind the Wunderlist to-do list app, for between $100 million and $200 million, according to a person familiar with the deal. The purchase is part of Microsoft’s new effort to enhance its line of mobile apps. It has recently started offering the mobile version of Microsoft Office free and acquired two makers of mobile apps: San Francisco-based Acompli Inc., which makes mobile-email applications, and Sunrise Atelier Inc., a New York-based startup behind the popular Sunrise mobile calendar application. Microsoft rebranded Acompli as Outlook for mobile. 6Wunderkinder is backed by investors including Sequoia Capital, a U.S. venture-capital firm, as well as European VCs Atomico and Earlybird Venture Capital GmbH. All the apps work on Apple Inc.’s iOS as well as Google Inc.’s Android operating systems, both of which compete with Microsoft. All three acquisitions point to an integration of Microsoft productivity tools, with an emphasis on mobile apps, the person said. On May 20, 6Wunderkinder announced a tie-up with Sunrise, meaning that users could now see their to-do lists in the Sunrise app, and also create to-do items from their Sunrise calendar app.