Privacy Policy

For the Blunderloop app and blunderloop.jandeboer.de. Last updated: 4 November 2026

Blunderloop collects no personal data. There is no account, no advertising, no tracking and no analytics. Your games, positions and progress stay on your device. This page explains the few connections the app makes and what happens when you visit this website or contact us.

1. Controller and contact

Jan de Boer
c/o Block Services
Stuttgarter Str. 106
70736 Fellbach
Germany
Email: contact@jandeboer.de

2. Data on your device

Blunderloop stores imported games, the positions it found, your training progress, streak and settings locally on your iPhone. The analysis runs on the device with the built-in Blunderloop Engine. For the widgets, the app writes a small summary (due positions, streak, the current position) to storage shared only between the app and its widgets. Reminders are scheduled as local notifications by iOS after you allow them; there is no push server. Local data may be part of the device backups you set up yourself.

3. Loading your games (Lichess and Chess.com)

When you enter a Lichess or Chess.com username, the app requests that player’s public games directly from lichess.org or api.chess.com. These services receive the request like any visit from your device, including your IP address, and process it under their own privacy policies (Lichess, Chess.com). We do not receive this data.

Optionally you can add a Lichess API token you created yourself, to load games faster. It is stored only in your device’s keychain and sent only to lichess.org.

4. Event puzzles

To show curated puzzles from current chess events, the app downloads one static file from blunderloop.app, a server operated by us. The request contains no identifiers, account or usage data. As with any web request, the server technically receives your IP address to deliver the file; we keep no access logs and do not use it to identify you.

5. App Store and purchases

Download, the free trial and the one-time purchase are handled by Apple through the App Store. We receive no payment details. The app asks Apple only whether the purchase exists on your Apple Account. Apple may provide us with aggregated statistics and crash reports you agreed to share. See Apple’s Privacy Policy.

6. This website

This website is hosted on our server at Hetzner Online GmbH in a data centre in Germany. To deliver the pages, the server processes technically necessary data such as your IP address, time and requested page. We keep no access logs, set no cookies and use no analytics, fonts or other content from third parties.

7. Contacting us

If you email us, we use your email address and message only to answer you, and delete the correspondence when it is no longer needed, unless we are legally required to keep it.

8. Legal bases

Providing the app functions you request: Art. 6(1)(b) GDPR. Secure delivery of the website and the event file and answering enquiries: Art. 6(1)(f) GDPR (our legitimate interest in a working, secure service). Legal retention: Art. 6(1)(c) GDPR. We do not sell personal data.

9. Deleting your data

Open Settings → Delete all data …, or delete the app. We hold no copy of your app data.

10. Your rights

Under the GDPR you have the right to access, rectification, erasure, restriction, data portability and objection. Contact us at contact@jandeboer.de. You may also lodge a complaint with a data protection authority, for example the State Commissioner for Data Protection Baden-Württemberg.

11. Changes

If the app or this website changes how data is handled, we update this policy before the change takes effect. The German version is here.