Chain

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. On Windows, uninstalling can leave the local database on your disk. On Android, uninstalling removes the app’s local data.

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;
• your standing Commission, if you keep one Public: the project it is on, its title, and the hours and days it has taken. What you wrote as its Charge is never published while it is running. A Private commission never leaves your device;
• your delivered Works — the frozen record of a completed Commission (its title, its Charge, the project, and the numbers as they stood the day you delivered it) — visible only to friends you've linked with, and deletable by making the Work Private;
• live presence (whether a timer is running) shared only with your friends, only while you're signed in — including the name of the project you are working on, if you have turned the "share my project" setting on.

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 links open Chain's Cartog feedback board in your browser, where feedback is visible to other visitors. Chain does not attach your account details, install id, or app version to this link. Older app versions used an in-app form; those submissions remain privately stored with the message, optional contact details, app version, operating system, and random install id.

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

We measure page views, demo use, download-link clicks and successful waiting-list submissions to understand how people find Chain. Reports include the page category, platform, app version, a broad source such as Google or Reddit, a recognised campaign label from our promotional links, and an approximate country supplied by our hosting provider. We do not save the full referring address, arbitrary link parameters, IP address, precise location, email, or a visitor identifier in these measurement records. A random identifier belongs to each event only, so a retried request is not counted twice.

Website measurement uses no cookies, browser storage, fingerprinting or cross-site tracking. It stays separate from app accounts and installation usage reports. We honour browser Do Not Track and Global Privacy Control signals. New website measurement records are automatically removed after 180 days. Only private aggregate reports are available to the operator. Our hosting provider may separately retain technical request logs to operate and protect the service.

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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