Microsoft has agreed to acquire 6Wunderkinder GmbH, a Berlin-based startup behind the Wunderlist to-do list app, for between $100-200 million, the Wall Street Journal reported yesterday. Quoting a person familiar with the deal, the daily said the purchase was part of Microsoft's drive to enhance its line of mobile apps. In March, Microsoft acquired the Californian start-up LiveLoop and its app that allows multiple users to collaborate on PowerPoint presentations simultaneously. Created in 2010, Wunderlist allows users to create lists to manage tasks on many devices, mobile as well as desktop.