This tool is designed to help teaching students the basic ideas behind how probability distributions work. It provides an easy-to-use interface that lets the user specify and then plot the graphs of various discrete or continuous variables. The graphs are interactive, and the user can view the probabilities of individual values, or of entire tails (for example P(X < 3)). Currently supported distributions are Binomial, Poisson, Negative Binomial, Geometric and Normal.
This tool is build using React + create-react-app, with D3 used for the interactive graphs. It is hosted for free here.