Privacy Policy

Last updated: March 2026

1. Data Controller

Martin Rost
c/o flexdienst – #20426
Kurt-Schumacher-Straße 76
67663 Kaiserslautern
Email: [email protected]

2. What data does ContactKeeper process?

ContactKeeper exclusively processes the contact data stored on your device. The app accesses your address book via the iOS Contacts API to display, export and import contacts. No contact data is transmitted to our servers or third parties.

3. Local data processing

All contact data is processed exclusively on your device:

  • Export files (CSV, vCard, JSON) are created locally
  • Import files are read locally and written to the iOS address book
  • Duplicate detection takes place exclusively on the device
  • Group management uses the native iOS Contacts API

4. Third-party services

4.1 RevenueCat (In-App Purchases)

We use RevenueCat (RevenueCat, Inc., USA) to manage in-app purchases. RevenueCat processes:

  • An anonymous app user ID
  • Purchase receipts (Apple Receipt)
  • Device type and operating system version

RevenueCat has no access to your contact data. Privacy policy: revenuecat.com/privacy

4.2 TelemetryDeck (Analytics)

For privacy-friendly usage statistics, we use TelemetryDeck (TelemetryDeck GmbH, Germany). TelemetryDeck collects:

  • Anonymized usage signals (e.g., which screens are opened)
  • Device type and operating system version
  • App version

TelemetryDeck collects no personal data, no IP addresses and no contact data. Privacy policy: telemetrydeck.com/privacy

4.3 Umami (audience measurement on this website)

For audience measurement on this website we use Umami. We host the software ourselves on our own server in Germany — no data is passed on to third parties. We record:

  • Page visited and referring source
  • Browser, operating system and device type
  • Screen resolution and language setting
  • Country of origin

Umami uses no cookies and stores no IP addresses. This data is not combined into a user profile, nor is it used to recognise you across other websites. The legal basis is our legitimate interest in a data-minimising analysis of website usage (Art. 6(1)(f) GDPR). You can object to this measurement at any time by using a content or script blocker.

4.4 Web3Forms (contact form on this website)

We send the contact form on this website via Web3Forms, a service provided by Web3Creative, based in India. The following data is transmitted:

  • Name
  • Email address
  • Message text
  • Technical transmission data (IP address, timestamp, referring page)

We process this data in order to answer your enquiry. The legal basis is Art. 6(1)(b) GDPR where the enquiry concerns a contract or steps taken prior to entering into one, and otherwise our legitimate interest in responding to enquiries (Art. 6(1)(f) GDPR).

A data processing agreement under Art. 28 GDPR is in place with Web3Creative. As the company operates from India and its service providers process data in several regions, transfers to third countries are safeguarded by the European Commission's Standard Contractual Clauses (Implementing Decision (EU) 2021/914). The following parties are involved in delivery:

  • Amazon Web Services (hosting, storage and email delivery)
  • Cloudflare (delivery and attack protection for the form endpoint)
  • Hetzner Online GmbH (application infrastructure, data centres in the EU)
  • CleanTalk and Akismet (Automattic) for spam prevention — both receive the sender's IP address and email address and process them in the USA

Your message is delivered to us by email. The service additionally stores it and deletes it automatically after three years at the latest. In our mailbox we delete it as soon as your enquiry has been dealt with and no statutory retention obligations apply. Privacy policy: web3forms.com/privacy

You do not have to use the form: an email to [email protected] reaches us without going through this service.

5. Permissions

ContactKeeper requires the "Contacts" permission (CNContactStore) to access your address book. This permission is requested on first launch and can be revoked at any time in the iOS Settings.

6. Your rights (GDPR)

You have the right to:

  • Access to stored data
  • Rectification of inaccurate data
  • Erasure of your data
  • Restriction of processing
  • Data portability
  • Object to processing

Since ContactKeeper does not store any personal data on our servers, these rights primarily concern the third-party services named above.

7. Contact

For privacy-related questions, reach us at: [email protected]