A super simple explicit single-particle time-dependent Schrödinger equation solver/viewer.
I used this to play around with multi-level Rabi problems in the (perturbed) infinite square well and wrote a term paper about my findings for a class. You can read NumericalRabi.pdf for details, or just watch an animation of the wavefunction's PDF jiggling between 3 states by running:
$ python3 -m toad_seer
from this directory. You'll need numpy and matplotlib.