The independent parameters of the problem are the shape of the spinning body (actually the ratios of the two principal moments of inertia), gravity, and the initial values of elevation, spin rate and precession. The dynamics are obtained by numerically solving the rigid-body equations of motion.
The available controls are start/stop and reset buttons, sliders for specifying the five parameters (changing a value restarts from the initial state), and the option to display a trace of the trajectory.