Privacy Policy
BookZEN, by InnoWave SRL (Innowave Solution). Effective 11 September 2026, updated 22 October 2026. Applies to the Android and iOS apps, and to this website and its support form.
BookZEN is a reading companion. It has no accounts and no sign-in. Your books, notes, reading log and photographs stay on your phone unless you choose to share them. This page says what leaves the phone, who receives it, why, and how to have it removed.
1. What stays on your phone
- Your shelf: the books you add, their status, ratings, notes and quotations.
- Your reading log: sessions, pages, streaks and the yearly challenge.
- Photographs you take of your own books: covers, spines, page edges and shelves. They are stored in the app's private folder. Only a spine or page-edge photo you choose to share with other readers is uploaded (see section 2).
- Reading a shelf photo: the spines are read on the phone with Apple's or Google's text recognition, and only the words read are used to look the books up.
- On iPhones and iPads that support Apple Intelligence, book and month summaries are written on the device.
- Your settings: reminders, goals, language, the look of your bookcase.
Ebooks and audiobooks you import, and any you download from a free public catalogue, are stored only on your phone, inside the app's private storage. They are never uploaded. Removing the file in the app deletes it, and so does deleting the app.
On iOS you can turn on iCloud sync. Your library is then kept in your own private iCloud account, by Apple, so it reaches your other devices. We cannot read it. Turning sync off stops it, and you can delete the copy from your iCloud settings.
Deleting the app deletes everything on the phone. Apart from what is listed below, there is no copy on our servers.
2. What leaves your phone, and who receives it
| What | Sent to | Why |
|---|---|---|
| An anonymous install identifier, app events such as “session started”, “book added”, “paywall viewed”, and device details (model, OS version, app version, language). Book titles you add and search terms you type may appear in these events. | PostHog and Google Firebase Analytics | To understand how the app is used and improve it. No name, email or account is attached, because none exists. |
| When the app crashes, a technical crash report: the code that failed, the app version and the device model, with the same anonymous identifier | PostHog | So we can find the fault and fix it. A crash report contains nothing from your books or notes. |
| For a share of new readers, a recording of the first onboarding and its offer screen: the screens you see and where you tap. Everything you type, including your name, is hidden in the recording, and so is every photo. | PostHog | To see where the onboarding is unclear. Nothing is recorded after onboarding. |
| Your purchase and subscription state, and the same anonymous identifier | RevenueCat, and Apple or Google as the store | To grant BookZEN Pro and restore it on a new phone. We never see payment details. |
| Purchase, renewal, cancellation and refund events for BookZEN Pro, with the same anonymous identifier | PostHog, passed on by RevenueCat | To count purchases alongside the app's other events. They are never linked to a name or email. |
| Older versions only (iOS up to 1.4.2, Android up to 1.4.3): the advertising identifier of your device (IDFA on iOS, only if you allowed tracking; Advertising ID on Android), install and launch events, and standard events such as completing onboarding, searching, finishing a book, starting a trial or subscribing (with the price) | TikTok for Business | To measure whether a TikTok advertisement brought you to the app. Newer versions (iOS 1.4.3, Android 1.4.4 and later) send nothing to TikTok, and the iOS app no longer asks to track you. |
| Android 1.4.5 and iOS 1.4.4 and later: your device's advertising identifier (Advertising ID on Android; IDFA on iOS, only if you tapped “Allow” on the tracking prompt), install and launch events, the purchases you make in the app (product and price, as Google Play or the App Store reports them), finishing onboarding and opening an offer screen | Meta (Facebook and Instagram advertising) | To measure whether a Meta advertisement brought you to the app, and to show our advertisements to people likely to enjoy it. No book, note or search is sent, and no screen titles. |
| The title, author or ISBN you search for, scan, or that is read from a photo of your shelf | Public book catalogues run by third parties, some through our own server | To find the book and its cover, pages and details. The query is used to answer the search and is not kept by us. A catalogue sees the query and your network address, as any website you visit does. |
| Cover images | The same catalogues and their image hosts | To show the cover. |
| The pages of a free-book catalogue you open, a search you type into it, and the file you choose to download | Free public catalogues such as Project Gutenberg, contacted directly from your phone when you browse them | To list the catalogue and fetch the book. The catalogue sees the same standard request data as any website you visit (your network address, the app's user agent). BookZEN sends nothing about you to it. |
| A spine or page-edge photo you choose to share with other readers, with the book's title, author and ISBN, the words read from the photo on your phone, and the anonymous identifier | Our own server | So other readers with the same edition can use it. Sent only after you agree to share. A person checks every photo before anyone else can see it, and any reader can report one. |
| Feedback you write in the app, with the app name and version, its language and your phone's, and the anonymous identifiers | Our own server | To read it and reply. Sent only when you tap send. Our replies are kept on our server against the app's random identifier, so the app can show them to you. |
| On this website: the page you visit, the page that sent you there, your browser and device type, and which store button you press | PostHog | To count visits and store-button clicks. The website sets no cookies and stores no identifier in your browser, so a visit is not linked to you, to your other visits or to the app. |
| A message you send from the support form on this website: your email, the subject and message, and your name if you give it | Our own server | To read it and answer you by email. Sent only when you press Send message. |
Several of these services derive an approximate, city-level location from your network address on their side. The app itself never asks for your location.
3. Advertising and tracking
The Android app from 1.4.5 and the iOS app from 1.4.4 include Meta's measurement software, to know whether our Instagram and Facebook advertisements bring readers who stay and subscribe. On Android it uses your phone's Advertising ID, which you can reset or delete in your phone's settings (Settings → Privacy → Ads, or Google → Ads). On iOS the app asks once, after onboarding, whether it may track: it uses the advertising identifier only if you tap “Allow”, and you can change your answer at any time in Settings → Privacy & Security → Tracking. With “Ask App Not to Track”, Meta receives the events without that identifier and counts them only in aggregate, through Apple's SKAdNetwork and Meta's Aggregated Event Measurement. Either way, Meta receives only the events listed in section 2. iOS 1.4.3 sends nothing to advertising networks. Older versions included TikTok's measurement software, to know whether our TikTok advertisements worked. On iOS it used the advertising identifier only if you tapped “Allow” on the tracking prompt, and otherwise relied on Apple's SKAdNetwork, which reports nothing about you individually. On Android it used the Advertising ID, which you can reset or delete in your phone's settings. Updating the app ends it. We do not show advertisements inside the app, and we do not sell your data.
4. Children
BookZEN is not directed at children under 13, and we do not knowingly collect data from them.
5. Retention and deletion
- Everything on your phone: gone when you delete the app.
- Analytics events, crash reports and first-session recordings: retained by PostHog (and the events by Firebase) under their standard periods, and never linked to a name.
- Subscription records: retained by RevenueCat and the store for as long as the subscription and its receipts require.
- Feedback and our replies: retained until we have dealt with it.
- Shared spine and page-edge photos: kept while they help other readers, and removed if you ask, or if they are reported and turned down.
To have server-side data about your install removed, write to us with the device identifier shown under Profile → Developer, or simply tell us the approximate date and what you sent, and we will do what we can. We cannot identify you from a name alone, because we never had one.
6. Your rights
If you are in the EU/EEA, the UK or another region with data-protection law, you have the right to access, correct and erase data about you, to object to processing, and to complain to a supervisory authority. Write to the address below to exercise them.
7. Security
Everything the app sends travels over encrypted connections. Keys for the services above live on our server or are restricted to the app, not exposed in the app.
8. Changes
When this policy changes, the effective date at the top changes with it, and material changes are noted in the app's release notes.
9. Credits
Two of the app's reading sounds are used under Creative Commons licences:
- Fire: “loopedfire1” by stratcat322, freesound.org/s/233189, licensed under CC BY 3.0. Shortened and loudness-adjusted.
- Café: “jazz-background-music-loop” by migfus20, freesound.org/s/564001, licensed under CC BY 4.0. Cut to a 60-second loop and loudness-adjusted.
The forest and rain sounds are in the public domain (CC0).
10. Contact
InnoWave SRL · support@innowavesolution.com
Third-party policies: PostHog, Firebase, RevenueCat, TikTok for Business (older versions), Meta, Apple iCloud.
Book data comes from ISBNdb, Open Library, Inventaire, NeoDB and Google Books. Free books come from public catalogues such as Project Gutenberg and LibriVox (through the Internet Archive), and from any OPDS feed you add yourself; the app contacts them directly from your phone when you browse them, with the same standard request data as any web request (your network address, the app's user agent), and sends them nothing about you.