Currently, this command-line tool displays statistics of word usage. It expects to get a file of words with their parts of speech and lemmas. It can be used with output of this POS tagger and lemmatizer: http://staffwww.dcs.shef.ac.uk/people/A.Aker/activityNLPProjects.html.
ruby word_stats.rb input.txt > output.txt
It can also be run with a list of already known words:
ruby word_stats.rb input.txt known_words.txt > output.txt
This tool was developed with Ruby 2.3.1. Other Ruby versions were not tested.