Privacy policy for the Bookjournal app

Last updated: October 31, 2026

  1. Controller
  2. Overview
  3. Your library on your device
  4. Book search and covers
  5. Camera for ISBN scanning
  6. Optional account and sync
  7. Export and import
  8. Service providers and third countries
  9. Retention and deletion
  10. Your rights
  11. Changes

1. Controller

Markant Software UG (haftungsbeschränkt)
Managing director: Max Markant
Horchheimer Höhe 45, 56076 Koblenz, Germany
Email: contact@markantsoftware.de

2. Overview

Bookjournal is a private reading journal. Your library, ratings and thoughts generally stay on your iPhone.

3. Your library on your device

The app stores books, reading status, reading periods, ratings, criteria, impressions, quotes, reviews and your settings in a database on your iPhone. We have no access to it. Whether this data is included in your iCloud or computer backup depends on your iOS settings.

When you search for a book or open book details, the app queries public book databases:

The provider receives your search term (title, author or ISBN) or the book’s identifier, together with technically necessary connection data such as your IP address and device information. The app loads book covers directly from these providers. The providers process this data under their own responsibility; see the Google privacy policy and the Internet Archive terms.

The legal basis is Art. 6(1)(b) GDPR, because search is an app feature you request.

5. Camera for ISBN scanning

When you scan a book’s barcode, the app uses your camera – but only after you have allowed access in iOS. The camera image is analysed only on your iPhone and is neither stored nor transmitted. Only the recognised ISBN is sent to the book databases, just like a manual search. You can revoke camera access at any time in the iOS settings.

6. Optional account and sync

An account is optional. It lets you back up your library and use it on several devices. Depending on how you sign in, we process:

We also store technical account data such as your user ID, the time of registration and last sign-in, and the IP address used to sign in (to protect against abuse). Sign-in emails are sent through the email delivery service Resend (Plus Five Five, Inc., USA) as our processor; Resend receives your email address and the content of the email for this purpose.

Sync: Your library only leaves your iPhone once you explicitly agree to sync. We then store your books (with book data and cover addresses), reading status and periods, ratings, impressions, quotes, reviews, custom criteria and settings on our server so they match across your devices. Only you can see this data.

The legal basis is Art. 6(1)(b) GDPR; for the IP address Art. 6(1)(f) GDPR (account security).

7. Export and import

You can export your library as a JSON file and save or send it using the iOS share sheet. The file is not encrypted; you decide where it goes. When importing, the app only reads the file you select.

8. Service providers and third countries

Account and sync are operated by Supabase, Inc. as our processor (Art. 28 GDPR). The data is stored in a data centre in Frankfurt am Main, Germany.

Some of the providers named here are based in the USA or may access data from there. We base such transfers on the European Commission’s adequacy decision for the EU-US Data Privacy Framework where the provider is certified, and otherwise on the EU Standard Contractual Clauses (Art. 46(2)(c) GDPR). Queries to Open Library are made at your request to carry out the search you asked for (Art. 49(1)(b) GDPR).

We do not share your data with any other third parties unless we are legally required to.

9. Retention and deletion

You delete data on your iPhone in the app or by removing the app. You can delete your account at any time in the app under Settings → Delete account. This immediately removes your account and all data synced with it from our server. Our provider’s backups are overwritten automatically according to its retention periods.

10. Your rights

You have the right of access (Art. 15 GDPR), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18), data portability (Art. 20) and to withdraw consent with effect for the future (Art. 7(3) GDPR).

Right to object: Where we process data on the basis of Art. 6(1)(f) GDPR, you may object at any time on grounds relating to your particular situation (Art. 21 GDPR).

For any request, an email to contact@markantsoftware.de is enough. You may also lodge a complaint with a supervisory authority, for example Der Landesbeauftragte für den Datenschutz und die Informationsfreiheit Rheinland-Pfalz, Hintere Bleiche 34, 55116 Mainz, Germany, www.datenschutz.rlp.de.

11. Changes

When the app changes, we update this policy. The version published here applies. We will inform you about material changes in the app.