Last month, Google announced new a 3D mapping service, followed shortly after by Apple’s announcement that it has built its own mapping service with 3D features for the next iOS, booting Google out for good. Now, Amazon appears to have taken the first step towards joining the mobile mapping service war, by acquiring 3D mapping startup UpNext.

GigaOM reports that Amazon closed a deal with UpNext on Monday, indicating that it could be bringing its own maps app to the Kindle Fire tablet. The aquisition also hints at a GPS version of the Kindle, and perhaps an Amazon smartphone.

It is not yet known how much Amazon paid for the acquisition, but reports suggest that investors are getting a five times return on their investment from 16 months ago.

UpNext was founded in 2007 by four school friends in New York to offer interactive, detailed 3D maps of cities and venues. The company already has iPad, iPhone and Android apps, and has worked with NFL to provide 3D maps for Super Bowl visitors. UpNext is now being relocated to Seattle as part of the acquisition terms, says GigaOM.

Apple’s new mapping service is set to arrive this autumn with iOS 6.