Tsuzuru

Privacy Policy

Last updated: 2026-09-08

1. What is never sent

The app does not send any of the following to the developer or to third parties.

• Photos, text, and arrangement of books you have not published
• The contents of your photo library
• Personally identifying information such as your name, email address, phone number, or postal address
• Precise location obtained through device location services such as GPS (the approximate region Firebase derives from an IP address is described in section 5)
• Contacts

The app does not ask you to create an account. There is no sign-in. If you share an exported video or book through another app, that destination's policy applies to what you share there.

2. What is sent when you publish a book

Only when you choose to publish a specific book, the following is sent to and stored on the developer's server (hosted on Cloudflare).

• The cover image and a book file — the book file contains re-rendered photo images (JPEG), text, page order, the book title and the paper theme you chose
• The book title and page count — used to display the publication page and manage publishing
• A random per-installation identifier — links published books to the installation for managing and unpublishing books, verifying purchased features and preventing abuse
• The IP address you published from — used to prevent bulk publishing and abuse, and stored in the active book's management data and publishing-limit records
• The result of verifying that the request came from a genuine copy of the app (Apple App Attest / Google Play Integrity)

The original photo files are never sent. Images are re-rendered by the app, so Exif data such as the original capture time and location is not carried over. Written text is included as text in the book file.

When you unpublish, the cover, book file and title are deleted from the server. When the publication period ends (90 days without the purchase, 365 days with it), access stops and scheduled cleanup deletes these files and records. The association between a public ID and its installation identifier is kept for 400 days after publication to allow reuse of the URL. Per-IP publishing-limit records are kept for 400 days after their last update. Identifiers needed to block abusive publishers are kept while the restriction is necessary.

When you publish using purchased features, the app sends the product ID and store-issued proof of purchase with the installation identifier to our server for verification. The verification result is associated with that identifier for 90 days and refreshed on another verification. The developer does not receive payment details such as credit card numbers.

3. What is stored on your device

Your books, the themes you chose, and publication state are stored in a database on your device. The random per-installation identifier is stored in the Keychain on iOS and in the app's settings storage on Android.

4. Device features

• Camera and photo library — used only to put photos into a book. Only the photos you pick are read; the library is not scanned.
• Motion sensor — used only for the light that moves across the paper. Nothing is sent off the device.
• Adding to the photo library — used only when saving an exported video.

5. Usage and crash reporting

The app uses Firebase Analytics and Firebase Crashlytics to improve features and investigate problems. After the app launches, the following is sent to Google (Firebase).

• Which features are used and how often — screens opened, books published, videos exported, limits reached
• Identifiers generated for app analytics and crash reporting — used to count usage and diagnose problems. The publishing installation identifier is not set as a Firebase user ID
• Approximate region — such as country or region derived from an IP address, without using device location services
• Crash and diagnostic information — where an error occurred, stack traces, preceding actions, device model, OS and app versions, performance and SDK operational information

We do not include your photos, words or book titles in analytics events. We record that a book was published and its page count, not what was in it. We do not set a name or account identifier as a Firebase user ID.

For Firebase's handling of this information, see Privacy and Security in Firebase.

6. Advertising and tracking

The current app and the web pages of published books display no advertising. The app does not include the AdMob SDK.

We do not link app data with data from other companies' apps or websites for advertising or advertising measurement, and do not provide it to data brokers. The iOS app does not obtain the advertising identifier (IDFA) and does not request App Tracking Transparency permission.

7. Pages of published books

When a published book is viewed, the server records only an aggregate view count for that book. No information identifying the reader, no per-reader history, and no cookie-based tracking. There is no way for readers to leave comments, ratings, or any other feedback.

8. Third parties

Published book files, covers, titles and the management data described in section 2 are stored on servers operated by Cloudflare, Inc. for hosting and publication management.

The app communicates with Apple's and Google's attestation services to verify that it is genuine. That communication contains none of your photos, words, or book contents.

Apple or Google processes purchases. We use store-issued proof to verify purchased features; Android verification also contacts Google's purchase-verification service.

Within the scope described in section 5, usage and diagnostic information is sent to Google (Firebase). We do not include your photos or written text in Firebase analytics events. We do not provide data to advertising providers.

9. Children's privacy

The app is not directed primarily at children. Unless you publish, the developer does not collect photos or entered text. Usage and crash information is handled within the scope of section 5 regardless of age.

10. Changes to this policy

If this policy changes, this page is updated and the date above is revised. If the information collected is expanded, this page is updated before that feature ships.

11. Contact

Questions about this policy, and requests to remove a published book: support@tsukuruya.me