The Stereoscope was first invented by Sir Charles Wheatstone in 1838. However, based on the existing product below a Stereoscope may be created and used by any smartphone taking two 2D images and making a 3D image. See Stereoscope. A Margolin Magnifying Video Visor, which can be easily transformed, and then photo capture and photo rendering software needs to be created per platform.
Compared to this Pocket stereoscope with original test image. Used by military to examine stereoscopic pairs of aerial photographs.
Another question, perhaps a more extensive version of this adopted tool may be used for 3D Scanning.