Stereograms are those strange patterned images where you don't see anything interesting, until you look behind the image.
When the image becomes out of focus, you see two images hence the name. The image has a repetitive pattern. When these patterns overlap (from the two images) you will see them clearly.
With this program, you can visualize these types of images and execute a series of actions - to rotate them, to animate them, to modify the color of the noise, etc.
A simple program that will keep you mystified for hours.