Privacy
The names you type stay in your browser. They are compressed into the part of the page address after the # sign. Browsers never send that part to any server, so the names do not appear in this site's logs, and they are not visible to your network or to a school's web filter. No request to this site or to any other carries them.
The names do live in the link. Your browser's history and bookmarks keep it, and if you sync those, so does your browser account. So does any link you copy, any email you send yourself, and any printout, whose QR code is the link. Anyone who has the link or scans the code can open the list. A copy is also kept in your browser's local storage so the page reopens where you left off; Start over removes it.
The site counts page views and anonymous usage, such as how often pairs are made, rounds advanced, people marked away, sheets printed, or links copied, and whether a visit came from a QR code or an emailed link, with a self-hosted analytics tool that sets no cookies and stores no personal data. It records the page visited, the referrer, the browser type, and the country. It never sees the names, and no usage count carries them.
There are no accounts and no cookies.