No analytics, no cookies, no fingerprinting, no pixels. This page and the app load from static files and phone home to no one.
There is nothing to sign up for, so there is no profile of you to keep, sell, or leak.
Your library lives in your browser's memory while you work and in .pack files you save yourself. If you use the backup feature, your packs travel directly from your browser to your own web hosting — configured by you, secured by your PIN, invisible to us.
So a crash or a closed tab doesn't cost you work, the app keeps a copy of the open library in your browser's own storage on your device. It goes nowhere else and we cannot see it. The switch — Keep a crash copy of the open library on this device — is on by default and sits on the start screen and in the sidebar; untick it on a shared or public computer and the copy is deleted immediately. Forget on the start screen does the same. Saving is still up to you: a resumed session is unsaved until you export or back it up.
The small card on the start screen linking to other projects by the same maker is a plain link. It carries no tracking parameters and fires no beacons.
Like nearly every website, the web host serving these files keeps standard access logs (IP address, page requested, time). We add nothing to that, and no third party receives it.
If any of the above ever changes, this page will say so plainly, in the same tone.