I have made several R packages to support my statistics teaching. These can be found below.

Johnson Neyman Plotting Tool for Conditional Effects

This is R package for students to plot conditional effects using the JN technique (via http://rpubs.com/bachl/jn-plot).

Skewness and Kurtosis

This R package calculates skewness and kurtosis for continuous variables in a manner that mimics SPSS.