Howl is interesing booklet that gives us a very rules light version of Werewolf the Apocalypse.
The Tabletop Gaming Club ran a short game using these rules. Though the rules are not perfect they did provide a easy to run session that had the feel of Werewolf. Though we wouldn't recommend the rules for a campaign, for a one-shot short session the rules were functional. As a Pay what you want item, its well worth picking up.