Productivity app developer 6Wunderkinder has just announced a $4.2 million investment by Kazaa and Skype co-founder Niklas Zennström through his investment company Atomico.

“The investment will accelerate product development, with a focus on Wunderkit. Funding such as this is not easy to find, especially with the kind of core values Atomico has. It will ensure our products will redefine the productivity market again and again, and that we can source the best people on the planet to make it happen.”

Read the whole press release here.

Wunderkit

I’ve personally been awaiting Wunderkit — supposedly a robust project management and productivity system — for some time. I wrote about Wunderlist early on, as have other Macgasm writers. To-do list app Wunderlist has achieved popularity based on its simplicity, beautiful design, and free over-the-air syncing. Its sharing capabilities combined with its availability on major platforms in several languages makes it suitable for many group project applications.

It would seem that from the beginning 6Wunderkinder has been using Wunderlist as a free sampler to tempt the mobile app-using world, all the while using the features and scale of the Wunderlist deployment as a test run for a more substantial project. Their efforts have literally paid off, evidenced by the new deal.

Atomico means more than cash

But Atomico brings more than money to the table. Zennström’s history in the software world is all about connecting users and data at a global level. While the money is obviously a huge boon for 6Wunderkinder, Zennström no doubt brings a myriad of resources, expertise, and connections that will help Germany-based 6Wunderkinder’s development team execute productivity that can truly support professionals and companies across language and geographical borders.

No release date for Wunderkit has been announced, but the press release promises a reveal “in the coming weeks.” Those interested can sign up for information here.