The short version: the games run in your browser, your records stay on your device, and there is nobody at the other end keeping score.
Each game keeps a small record — games played, games won, a best time, a streak — in your browser's local storage, on the device you played on. The daily cryptogram also remembers which days you solved, so the streak can be counted. Every entry is filed under a name beginning pp_.
That record is never sent to us or to anyone else. It doesn't sync between your phone and your laptop, and it goes when you clear your browser data. To wipe it yourself, open your table and press forget everything.
Nothing. There is no account to make, no email address to give, no cookies, no adverts and no analytics script. The opponents, the shuffles and the solvers are all JavaScript running on your own device; no move you make travels anywhere.
Two ordinary things, both part of loading a web page at all:
After the first visit, a service worker keeps a copy of the site's own pages and game files on your device, which is why the table works on a plane. That copy holds only our files — never anything about you — and is removed when you clear the site's data in your browser.
The copy my record button on your table puts a few lines of text on your clipboard. Where it goes after that is up to you; the site itself sends it nowhere.
These are card and board games and anyone can play them. Since nothing is collected from anybody, nothing is collected from children either.
If anything here is unclear, or you find the site doing something this page doesn't describe, write in — that would be a bug, and it would get fixed.