The comprehensiveness and flexibility of this applet makes this work outstanding. The material covered includes some of the most interesting and hard to visualize in advanced physics. The available potential well options cover both standard examples and several less well studied. Essentially all physical parameters of the system, such as well width and depth and mass and charge of the quantum particle, can be adjusted. The user has extensive control over both the states and information provided, including probabilities, amplitudes, phases, expectation values, and uncertainties.
One important strength of this applet is the ability for the user to make "measurements" of position, momentum, or energy and view the subsequent propagation of the state. This provides an illustration of the important issues of quantum measurements and their impact on states.
This applet has a place in almost any advanced quantum-mechanics course.