Signing in is optional. Your stack always stays on this device — signing in only saves the contact details you choose to give us, so we can reach you about testing, prizes and orders.
Sign in (optional)All optional. Saved on this device only until you sign in. Nothing about your stack is ever uploaded.
Hide metals you don't stack. Hidden metals disappear from Holdings and the allocation chart.
Your stack lives only on this device. Export a JSON backup regularly — if you clear your browser, switch phones, or reinstall, this file is the only way to restore it.
Clearing history or cookies does not delete your stack — it lives in on-device storage. Only "clear site data", deleting the app, or wiping the device removes it.
Found something broken? Tell us what happened and we'll patch it — and you'll earn a Bug Hunter badge for the trouble.