Microsoft has introduced its 3D printing app for Windows 8.1 as promised. The app is definitely geared toward the consumer, offering what amounts to an introductory app for the home user. Hey, it works and it's free. If you don't like it, you get your money back.

The simple, simplistic, free app from Microsoft provides a basic way to print common 3D objects, as well as to import other files from SkyDrive or elsewhere. But the degree of customization that the app allows is small, so 3D Builder basically serves as an introduction to the world of 3D printing.

In fact, that's Microsoft's intention, with demonstrations of the MakerBot Replicator 2 slated for Microsoft's retails stores this weekend. Microsoft customers can buy a new Windows 8.1 PC, as well as the $2199 MakerBot Replicator 2, both online as well as in the brick-and-mortar stores themselves.

One of the selling points of Windows 8.1 was its ability to print 3D objects, a complement to traditional paper printing. Although Microsoft is pitching 3D Builder as a consumer app, the bulk of spending on 3D printing will come from businesses, which will account for $325 million out of the $415 million that will be spent this year on 3D printing, according to an October report from Gartner. However, 3D printers have made their way into Staples, and MakerBot latched onto an endorsement of the technology from President Obama during his State of the Union address, recently encouraging U.S. citizens to crowd-fund an effort to 3D printers in every high school in America. (MakerBot also announced a Windows 8.1 software driver on Thursday.)

Microsoft's 3D Builder app could certainly be a part of that effort. Frankly, there's little to the app itself besides a library of pre-selected objects, most of which seem to be built around small, unpowered model trains of the "Thomas the Tank Engine" variety. After selecting one, the user has the option of moving it around a 3D space, increasing or decreasing the size to a particular width or height—and not much else.

Users can also import models made elsewhere. Again, however, 3D Builder isn't really designed to modify the designs. It's also not clear which 3D formats are supported.