Coffee Rings
EN | DE

Privacy at Coffee Rings

Coffee Rings is designed to keep your data in your hands. All coffee and recipe information is stored under your control, and you decide whether features like cloud synchronization or AI support are used. The details are explained below.

Privacy Policy (App "Coffee Rings")

Effective date: November 2025

Contact

E-mail: support@coffeerings.de

Controller

Responsible for data processing within this app is:

Michael Karl Knop
E-mail: support@coffeerings.de

Data processed

The app “Coffee Rings” does not process any personal data that directly identifies you. The only data stored are:

  • Espresso recipes & shot parameters entered by the user
  • Optional notes or ratings related to your shots

This data is stored locally on your device by default. Optionally, users may:

  • Back up or restore recipes and settings via iCloud (CloudKit). In that case, data is stored on Apple’s servers in accordance with Apple’s privacy policies.
  • Export recipes and save them anywhere (e.g., locally, in another cloud service, or on external drives).

Storage & synchronization

The app works fully offline and does not require an account. If you enable iCloud for Coffee Rings in iOS (Settings → Apple ID → iCloud → Apps using iCloud → Coffee Rings), iOS/iPadOS will additionally sync your recipes into your private iCloud database (powered by Apple’s CloudKit service). Only you and your Apple ID can access this space — the developer has neither visibility nor control over it.

Apple merely provides the infrastructure. You can disable syncing or delete the stored cloud data at any time by removing iCloud access for Coffee Rings. Even without iCloud, all data stays on your device and can be backed up via exports or encrypted device backups.

Use of AI features (OpenAI)

The app optionally allows you to enter your own OpenAI API key to receive AI-based recommendations.

In that case, data is transmitted directly between your device and OpenAI’s servers.
Your API key stays in the app’s secure storage (and, if you enable iCloud for Coffee Rings, inside your private iCloud backup) and is only used when your device talks directly to OpenAI. The developer (Michael K. Knop) has no access to the API key, the transmitted input, or the AI output.

OpenAI may process or store data in accordance with its own policies. The scope of processing depends on the settings and agreements you, as the user, have with OpenAI (see OpenAI Policies).

No disclosure to third parties

The developer does not share any data with third parties. Any processing outside of the app (e.g., via OpenAI or the optional iCloud/CloudKit sync handled by Apple) happens solely when you enable those features. For exports, you decide where the files are stored (local drive, your own cloud, external media, etc.).

Your rights

Under the GDPR, you have the right to:

  • Access your stored data
  • Rectify inaccurate data
  • Erase your data
  • Restrict processing
  • Data portability

Since the app works locally, you can delete your data at any time yourself (e.g., by removing recipes, resetting settings, or uninstalling the app).

In-App Purchases (Tip Jar)

All payments are processed solely by Apple Inc. through your App Store account. The developer does not receive any personal data related to these purchases (such as name, address, or payment information). Apple acts as the data controller for these transactions under its own privacy policies. You can view your purchase history in your App Store account.

Changes to this policy

This privacy policy may be updated if necessary. The current version will always be available within the app and on the App Store page.