Privacy Policy
Last updated: July 2026
LeanBooks is built on the same principle as all LeanTools apps: your data is your data. That's not a tagline — it's a hard architectural constraint we imposed on ourselves from the start.
Controller
The party responsible for data processing under this Privacy Policy is: Jochen Köneke · Am Pfeilgraben 11 · 39171 Sülzetal · Germany · Email: support@greyhead99.com
Data We Collect — The App
LeanBooks does not collect any personal data. All book data is stored exclusively on your device and in your personal iCloud account. We have no access to your library, lending records, wishlist, or any other content you create in the app.
Data We Collect — This Website
When you visit this website, our hosting provider (Strato AG, Pascalstraße 10, 10587 Berlin, Germany) automatically records standard server log files. These contain your IP address, the date and time of your request, your browser type, and the page you requested. This data is used solely to ensure the secure and stable operation of the website and is deleted after a maximum of 7 days. Legal basis: Art. 6(1)(f) GDPR — our legitimate interest in operating a secure website.
Language Preference
This website stores your language preference (preferredLang) locally in your browser using localStorage. No personal data is transmitted to us or any third party as part of this.
iCloud Sync & Sharing
When you use iCloud sync or the Family Library sharing feature, your data is transferred via Apple's iCloud infrastructure under Apple's Privacy Policy (www.apple.com/legal/privacy/). Apple acts as an independent data controller for this processing. We do not operate any servers involved in this process. Apple Inc. is based in the United States; data transfers from the EU to the US are covered by Apple's certification under the EU–US Data Privacy Framework (www.dataprivacyframework.gov/participant/4000).
Analytics
LeanBooks does not use any third-party analytics SDKs. We use App Store Connect's built-in aggregate statistics — provided and operated by Apple Inc. — to understand general usage trends. Apple processes usage data (such as device type and app version) before we receive any information; what we see is anonymised and aggregated. Apple acts as a separate data controller for this processing.
Purchases
LeanBooks Plus subscriptions are processed entirely by Apple via In-App Purchase. We do not see or store your payment information. Apple acts as the merchant of record and an independent data controller.
Data Retention
We only retain personal data for as long as necessary for the stated purpose: server logs (website) for a maximum of 7 days, then automatically deleted; email correspondence (support) for up to 2 years after the matter is resolved, unless a longer retention period is required by law.
Transfers to Third Countries
Apple Inc. (iCloud, App Store Connect, In-App Purchase) is based in the United States. These transfers are covered by Apple's certification under the EU–US Data Privacy Framework. We do not otherwise transfer personal data outside the European Economic Area.
Your Rights
You have the following rights regarding your personal data: right of access (Art. 15 GDPR), right to rectification (Art. 16 GDPR), right to erasure (Art. 17 GDPR), right to restriction of processing (Art. 18 GDPR), right to data portability (Art. 20 GDPR), and right to object to processing (Art. 21 GDPR). To exercise your rights, please contact: support@greyhead99.com
Right to Lodge a Complaint
You have the right to lodge a complaint with a data protection supervisory authority regarding the processing of your personal data. The competent authority is: Landesbeauftragter für den Datenschutz Sachsen-Anhalt, Leiterstraße 9, 39104 Magdeburg, Germany (www.datenschutz.sachsen-anhalt.de). You may also contact the supervisory authority in the EU member state where you reside or work.
Contact
Questions about privacy? We're happy to answer them. Reach us at support@greyhead99.com