Kinemagics is a one dimensional kinematics simulator. It allows the user to pick from one of four preset movement patterns (reflective of a worksheet used in my physics class) or draw their own, and then observe how the displacement, velocity, and acceleration of an object with this movement change over time.
Although it's based on a physics class, I did this mostly just for the fun of it—to get a chance to work with Clojure and build a useful study tool.
Use it at wilsonberkow.com/kinemagics/.