This site collects nothing. There are no accounts, no cookies set by us, no trackers, and no analytics that identify you.
Quit dates, streaks and test answers are stored only in your browser's local storage on your own device. They are never transmitted to us, and we have no way to see them.
The only files your browser downloads are the public pages, stylesheets and scripts that make the tools work — the same as any website, minus the tracking.