To-do list app designer 6Wunderkinder has been acquired by Microsoft to improve productivity in a mobile-first, cloud-first world.

The German business said it will introduce new features into its solution, and will be integrated into Microsoft in the coming months.

The Wunderlist app is used by over 13 million customers worldwide, and is available as Wunderlist, Wunderlist Pro and Wunderlist for Business.

Eran Megiddo, GM for One Note at Microsoft, said that customers can expect the app to remain free in all of its existing markets.

He added that there will be no price changes for the Wunderlist Pro or Wunderlist for Business versions.

The solution can be used on most platforms including Apple’s products, Windows and on the web.

Christian Rebe, CEO at 6Wunderkinder, said: "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."

Microsoft has recently acquired other apps companies including Sunrise and Acompli.