Microsoft's push to grow its mobile productivity app-stable continues

Another week, another new Microsoft productivity app.

This week, rumors of Microsoft purchasing Berlin-based productivity app startup 6Wunderkinder are circulating again, with The Wall Street Journal claiming Microsoft officials have pulled the trigger and bought the company for somewhere between $100 million and $200 million. (I've asked Microsoft officials for comment. No word back so far.)

Update (June 2): It's confirmed that Microsoft has bought 6Wunderkinder. No price is being disclosed, but 6Wunderkinder officials are saying their app will remain available cross-platform.

6Wunderkinder makes a task-management application, called Wunderlist. Wunderlist already is available for iPhones, iPads, Macs, Android, Windows, Kindle Fire and the Web. Sunrise Calendar -- now owned by Microsoft -- as of today integrates Wunderlist tasks into daily views.

Microsoft is accelerating its focus on delivering new productivity-centric software and services. In the past couple of weeks alone, there have been leaks about Microsoft's plans to roll out a Web-based clipboard called OneClip; a calendar/contact-management mash-up called Revolve; a cross-platform email chat app called Flow; a lightweight project-management app currently known as "Highlander"; and a document-collaboration app that may be known as "Flip."

Microsoft also bought in recent months cross-platform mobile e-mail vendor Acompliand calendar app maker Sunrise.

Productivity in general, and team collaboration in particular, seem to be an increasingly important area of focus for Microsoft under CEO Satya Nadella.

A couple of recent Microsoft job posts have indicated the company is staffing up a new "Teamspace" group within its Applications and Services organization to work on "the next generation of innovative productivity applications." From what I can tell, in spite of the Teamspace name, this new group is not connected in any way to a company called 5 Point AG which has a team-collaboration app called Teamspace.

I asked both Microsoft and 5 Point for comment. A Microsoft spokesperson said the company had no comment; 5 Point never got back to me.

Microsoft recently removed content it had on the teamflux.io, teamflux.org and teamflux.ninja sites. The "Walking Cat" on Twitter (@h0x0d) captured an image of what he said could be a new Teamspace collaboration app from Microsoft. (I've embedded his Teamspace image above.)

Microsoft officials declined to comment when I asked about what Teamspace is.