Privacy policy

Last updated · 2026-07-11

Chain is local-first by design. The short version: your focus history lives in a database on your own machine, nothing is sold or shared with third parties for advertising, and the only data that leaves your device is what's needed to run the features you choose to use.

Data stored on your device

Your sessions, chain, XP, medals and settings are stored in a local SQLite database on your computer. Using Chain requires no account. Uninstalling the app removes the app; the local database stays on your disk until you delete it.

If you create an account

Signing in (email one-time code) enables sync and the friends leaderboard. We then store on our backend (Supabase, EU-hosted project):

your email address (for sign-in only — never sold, never used for marketing without your consent);
your synced session history, so your devices agree;
your public profile: display name, level, hour-rank, equipped cosmetics — visible only to friends you've linked with;
live presence (whether a timer is running) shared only with your friends, only while you're signed in.

Telemetry and feedback

The app sends small anonymous telemetry events (app version, feature usage counts, error reports) to help us fix bugs and understand what matters. These contain no session content and no personal identifiers beyond a random install id. Feedback you submit through the feedback door is stored with the text you wrote and your app version.

The Android waitlist

If you join the waitlist on this site, we store your email address for exactly one purpose: telling you when Chain for Android is available. One email, then you're free.

Analytics on this website

This site sets no advertising cookies and uses no cross-site tracking identifiers. When first-party site measurement is enabled, it sends only a coarse event name, the page path and the event time — no persistent visitor id, email, fingerprint or referrer. Our hosting provider may also retain standard technical request logs and aggregate visit counts used to keep the site reliable.

Your rights

You can request a copy or deletion of your account data at any time. Deleting your account removes your synced history, profile and friendships from our backend; your local database remains yours. You can delete your account directly in the app (Settings → Delete account) — see how account deletion works — or contact: borisvanderkruk@gmail.com.

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