I have developed a few simulations that I've found useful for the classes I've taught. They are sorted below by general category. Maybe in the future I'll implement a more careful search and tagging system.

Electricity and Magnetism

Integral Form of Ampere's Law
This simulation shows how path integrals over vector fields work and uses the specific context of Ampere's Law and magnetic fields to demonstrate this.

Optics

Image Formation with Flat Mirrors
This simulation shows how images form with flat mirrors. You can observe the law of reflection in action and learn about the nature of virtual images. Working, but additional features planned!

Image Formation via Refraction (Observe the Paraxial Approximation)
See how images form when objects and observers are in different media. This sim doubles as a tool to visualize the importance of the paraxial approximation in optics.

Image Formation with Lenses
Form images with systems of lenses and observe the light rays converge and diverge. You can use converging or diverging lenses and insert up to four lenses and see how the resulting image forms.

Quantum Mechanics

Polarization
Visualize different polarization states across multiple representations, including visualizing the waves, seeing the polarization ellipse and the Poincare sphere, and decomposing into different bases. Play around with measuring polarized photons and manipulating polarization states with birefringent materials (coming soon).

Stern-Gerlach Experiments
Set up chains of Stern-Gerlach apparatuses and collect particle count data to investigate spin-1//2 particle behavior.

Violation of Bell's Inequality
Make entangled photon pairs and test Bell's inequalities. This sim uses SPDC-generated photon pairs and polarization entanglement.