wellspell.addin is an RStudio Addin to quickly highlight words with spelling errors in text documents. It employs the hunspell spell checking engine to do this. You can install wellspell.addin with
devtools::install_github("nevrome/wellspell.addin")
To use it, you can select an arbitrary amount of text in a text document in RStudio (e.g. a markdown, latex or html document) and run spellcheck(). As the function is registered as an RStudio Addin, it's possible to run it from the Addins dialogue or even with a keyboard shortcut (e.g. CTRL+ALT+7).
At the first run in a new environment, spellcheck() will call set_config(), which is another Addin with a minimalistic user interface. It allows you to set two environment variables wellspell_language and wellspell_format. These are used to configure hunspell::hunspell(). wellspell_language is fed to hunspell(dict = dictionary(lang = ...)) and wellspell_format to hunspell(format = ...).
If the environment variables are set, spellcheck() selects and thereby highlights all words identified as wrong by hunspell.
The additional functions get_config(), is_config() and rm_config are for dealing with the environment variables and usually don't have to be called directly.