Use(s) Material is not Suited For: Tutorial (not sufficient explanations of the physical system)
Students will probably need some guidance understanding what they can do with this applet. This is probably because this is more an example for instructors than students.
More unique questions about hydrogenic atoms can be explored using this excellent tool. For example, getting students to look at high N Rydberg states could be useful for thinking about the correspondence principal.
The questions regarding the dependence (or independence) of the wavefunctions on quantum numbers are moot since the wavefunctions are labeled by just the quantum numbers on which they depend.
The questions about the quantitative dependence of the peak in the wavefunction as a function of N will need some previous experience on the part of the student with the hydrogenic wavefunctions.
General Comments on Effectiveness: According to the author, these Physlets "can be used at the beginning of class to introduce topics, during the middle of a topic to test whether students are ready to cover additional material, or at the end of a topic to test students? knowledge of the material just covered." These give good examples of the ways in which this applet can be used. Instructors can build on these examples.