Check off achievements as you earn them. Missables are flagged before you can lose them, spoilers stay hidden until you tap, and multi-playthrough planners keep the road to 100% organized. Your progress saves automatically in your browser.
How progress saving works. Your checks are stored on this device by your browser — nothing is uploaded and no account is needed. To move progress to another device, open the guide there and use Export sync code / Import sync code at the top of any checklist. Clearing your browser's site data will clear saved progress.
Coming later: optional one-tap sign-in (Google or Apple) for automatic sync across devices — never a requirement, and never a password.