You draw a layout of virtual magnets in a png file and the program processes the fields. By using different colors, you pick which direction a magnet's magnetic moment is pointing and you can have many different magnets in different directions. The command line program processes the png file and displays the interacting magnet fields of the virtual magnets in your drawing. A command line program that you could use in a high school physics class and/or in a university spintronics class.
The free version accepts images of 640x640 and the Pro version for $29.95 accepts images of 1280x1280 and has options for thicker magnets. The free version can be used by everyone and everybody, including school computer labs around the world.