Microsoft launched a new app today called View 3D Preview. At the moment, it"s only available for Insiders on the Fast ring, and it"s PC-only. According to the Feedback Hub announcement, the app is meant to "enable everyone to easily open and view 3D models inside of Windows."
Note that there are some discrepancies between the Feedback Hub post and the Windows Store listing. Feedback Hub states that it"s only for Insiders on the Fast ring, but the Store says that it"s for all Insiders running build 14800 and up.
The announcement also says that it supports the FBX and 3MF file types, and it will only display in English no matter what your system"s language is. Of course, it"s in preview, so these things will get better with time. The Store listing says that it supports 3MF, PLY, OBJ, FBX, and STL files.
Unlike some app updates that appear for Insiders, this one isn"t likely to arrive for the general public until the Creators Update ships, which is slated for March.