Prettymapr automates the process of creating a scale bar and north arrow in any package that uses base graphics to plot in R, or provides parameters that help to draw scale bars and north arrows in other plotting environments. Bounding box tools help find and manipulate extents, and geocoding tools help plot locations on maps. Finally, there is a function to automate the process of setting margins, plotting the map, scale bar, and north arrow, and resetting graphic parameters upon completion.
The prettymapr package is available on CRAN, and can be installed using install.packages("prettymapr").
The prettymapr package was written several years ago and better tools to make publication-quality maps in R have been made available since its release. The prettymapr package should be considered deprecated and is in bugfix-only mode for the foreseeable future.