blunder.zone

Privacy Policy

Effective date: August 12, 2026

This Privacy Policy explains how Blunderzone collects, uses, stores, and deletes information when you use the Blunderzone mobile app, web app, API, and related services.

Privacy contact: ranka.sro@gmail.com.

Information we collect

• Account identifiers: your Blunderzone account id, passcode, device UUID, and linked lichess.org or chess.com usernames.
• Device information: basic device and operating system details used to connect your device to your account.
• Chess and training data: imported public chess games, OTB games you enter, puzzle attempts, ratings, streaks, settings, and training progress.
• First-party usage events: account creation and login, feature views, settings changes, puzzle activity, and subscription verification status. At account creation, an allowlisted acquisition campaign code may also be recorded so aggregate campaign activation can be measured. Passcodes and store verification payloads are not copied into these event records.
• Cookie-free website measurement: the date, one of four predefined events (landing page view or a click to the web app, App Store, or Google Play), and a predefined campaign code. These records do not contain an account, visitor or device identifier, IP address, user agent, referrer, full URL, or free text. Page views are event counts, not unique visitor counts.
• Service logs: API requests, diagnostics, and security records needed to operate and protect the service.

How we use information

• To create and secure your Blunderzone account.
• To import games and generate training puzzles.
• To remember settings, progress, ratings, and streaks.
• To maintain, debug, protect, and improve the service.
• To measure whether the public website helps people reach the Blunderzone app or an app-store page, and whether aggregate signups from an allowlisted campaign reach a first training action.
• To respond to support, privacy, and deletion requests.

Blunderzone does not sell personal data and does not use collected data for cross-app or cross-site tracking. The public website measurement does not use cookies, browser storage, fingerprinting, or third-party analytics scripts.

Sharing

We share data only where needed to provide the service: Public chess platforms are contacted to import games for usernames you link. We may also disclose information if required by law or to protect the service and its users.

Security and retention

The app uses HTTPS for server communication and encrypted local storage for cached account data. We keep account and training data while your account is active. Usage events linked to your account are removed when the account is deleted. Anonymous daily website counts may be retained for trend comparison because they cannot be linked to an account or visitor. Service logs are kept only as long as needed for operations, security, and debugging.

Deletion

You can delete your account in the app from Settings - Delete account. This removes your Blunderzone account, passcode, linked devices, linked chess accounts, training progress, settings, streak data, and OTB games associated with your account. Imported public chess games may remain in service caches if they are not uniquely tied to your account.

If you cannot access the app, follow the instructions at account-deletion.html.

Children

Blunderzone is not directed to children under 13. Do not use the service if you are not old enough to create an account under the laws that apply to you.

Changes

We may update this policy when the app, legal requirements, or store requirements change. The effective date above shows the latest version.