The goal of geotools is to provide simple support functions. They are mainly used in my {geographer} package.
You can install the latest version of geotools from GitHub with:
# install.packages("remotes")
remotes::install_github("Nenuial/geotools")
Or from r-universe:
install.packages('geographer', repos = c('https://nenuial.r-universe.dev', 'https://cloud.r-project.org'))
The package documentation is available at https://geotools.nenuial.org.