Pic2Mag

The user draws the magnets and the Pic2Mag program draws the magnetic fields. The Field Calculator program now has a Magnetostatic mode, and a Electrostatic mode to plot either magnetic fields or electric fields. The program designed to help students learn Magnetic fields and Electric fields. You can draw magnets and look at the magnetic field, or you can draw electric charges and look at the electric voltage field.

The app can process most images in just a few minutes.  The app caches it's results so the more that you use it, the faster the program processes images.

Red pixels represent magnets with a North pole surface facing the observer, and Blue pixels represent magnets with a South pole surface facing the observer. 

Pink pixels represent positive electric charges, and Dark Purple pixels represent negative electric charges