Privacy Policy

Last updated: October 29, 2026

Book Spotter (“the app”, “we”, “us”) helps you find books on shelves using your device's camera. This policy explains what information the app does and does not handle. Book Spotter is operated by Matthew Audette (CGE Computers LLC) and is available for iOS and Android.

The short version

Book Spotter is built to work on your device. Text recognition happens locally and your camera images are never uploaded or stored by us — the one exception is a shelf photo you explicitly choose to send with a report (see “Reports you send”). If you create an optional account, your email address and the book data you save are stored on our server so they can sync across your devices; you can delete your account and all of its data at any time. The app contains no third-party analytics SDK; it sends us a few anonymous usage counts (which features were used — never your books or what you typed; see “Analytics” below), and this website uses standard web analytics (Google Analytics and Microsoft Clarity — see “Website analytics” below). We don't sell your data.

Camera

The app uses your camera to recognize text on book spines and covers in real time — Apple's on-device Vision framework on iOS, Google's on-device ML Kit on Android. Camera frames are processed on your device to draw match boxes and are not saved, collected, or transmitted to us or anyone else.

Photos

If you use “Scan from Photos,” a photo you choose is processed on your device to find your target books within it. The photo is not uploaded to us and is not shared.

Accounts and sync

Creating an account is optional and is what enables cross-device sync, the web Book List portal, and library sharing. When you create an account we collect and store:

This data is stored on our server (hosted on Cloudflare) and is always encrypted in transit (HTTPS). Without an account, the books you add are stored only on your device.

Library sharing

If you share a library, the people you invite by email can see that library's contents (titles, authors, notes). Sharing is read-only and invite-only — nothing you save is ever public or discoverable.

Sharing books by link

If you use “Share” to send one or more books to someone, a copy of those books (title, author, desired condition, and your notes only if you turn on “Include my notes”) is stored on our server under a random, unguessable link such as bookspotter.app/s/… so the recipient can open it. Anyone who has the link can see those books, so share it only with people you mean to. A shared list is a one-time copy — later changes on either side don't affect it — and it is deleted from our server automatically 90 days after it was created, or sooner if you delete your account (when you were signed in while sharing). No account is needed to share or to open a share. Email [email protected] with the link to have a share removed early.

Book database lookups

When you tap “Check against book database,” the title and/or author text you typed is sent to Open Library, a free service operated by the Internet Archive, to retrieve matching book details. Only the text of your search is sent — no account, name, or device identifier. Open Library's handling of requests is governed by the Internet Archive's privacy policy. If Open Library finds nothing, the app also tells us the title and author you searched for (see “Reports you send”).

Reports you send

To improve the book database and spotting, the app sends us short reports containing only a book's title and author (plus the platform, which screen it came from, and — for a book that hasn't been spotted — how many scan sessions it has been searched for). It sends one automatically when a “Check against book database” search finds nothing, and when a book you're searching for hasn't been spotted after several scan sessions; each is sent at most once a week per book, and never includes a photo, your notes, or the rest of your list. You can also send one yourself: if you tap “Report: Book Spotter can't see this book,” the book's title and author are sent to us so we can study why that spine is hard to read. If the app then offers to send a photo of the shelf and you choose to, that one photo is uploaded for a person on our team to review; location and camera metadata are removed from it on your device first, and it is never shown to other users or used for advertising. If you are signed in, the report is attached to your account so we can follow up; otherwise it is anonymous. Email [email protected] to have a report or photo removed.

Purchases

Subscriptions are processed by Apple through the App Store (iOS) or by Google through Google Play (Android). We do not receive or store your payment details. The stores provide us only with the anonymous status of whether an entitlement is active.

Advertising

If the app shows ads (for example, an optional rewarded ad to unlock extra searches), those ads may be provided by Google AdMob. AdMob may collect device identifiers and usage information to serve and measure ads, as described in Google's Privacy Policy. You can control ad personalization in your device settings. Ads are not part of every version of the app.

Analytics

The app sends our own server a small number of usage events so we can tell which features are used and where people get stuck. Each event is an action name plus a few fixed-choice details — for example “app opened”, “scan ended after 30 seconds to 2 minutes, something matched”, “searching limit reached on the free plan”, “book unlocked with an ad”, “subscribed to the 25-book plan”, or “update banner tapped”. Events never contain book titles, authors, notes, anything you typed, your email address, or your photos, and they don't include an advertising or device identifier. The app stamps each event with its platform (iOS or Android) and app version; if you are signed in, events are linked to your account (that's how we leave our own test accounts out of the numbers), and if you aren't, they are anonymous. Events are kept in a short queue on your device and sent in batches; they are deleted with your account if you delete it. We use them only in aggregate, to improve the app — never for advertising, and they are never sold or shared.

The mobile app does not include a separate third-party analytics SDK. The Google AdMob advertising SDK (see “Advertising” above) may use device identifiers to measure ads and, with your permission, to track across apps and websites; you are asked for this permission through Apple's App Tracking Transparency prompt and can decline it while continuing to use every feature. Apple may also provide us with aggregate, anonymized App Store and crash statistics that cannot identify you.

Website analytics

This website — bookspotter.app, including the web Book List portal — uses two standard web analytics services to understand how it is used and where it can be improved:

Both set cookies in your browser and receive technical information such as your browser and device type, the pages you visit, and an approximate location derived from your network address. They do not receive your email address, password, or the contents of your book list: the events we send are action names and counts only (for example “CSV uploaded, 12 books added”), and in the portal your email address, the book table, and everything you type are excluded from Clarity recordings. These services run only on this website — the mobile apps do not include them.

To opt out, block cookies for bookspotter.app in your browser, use a content blocker, or install Google's Analytics opt-out add-on. The website and the portal work fully with analytics blocked.

Third-party services

Data retention and deletion

Camera frames and the photos you scan are processed transiently and never retained; the only photo we keep is one you explicitly chose to send with a report (see “Reports you send”), and you can ask us to delete it at any time. Books stored only on your device are removed when you remove them or delete the app. If you have an account, your synced data is retained until you delete it: remove individual books and libraries at any time, or delete your entire account — from the app, or from the web portal — which permanently removes your email address, book list, libraries, and shares from our server immediately.

Children's privacy

Book Spotter is not directed to children under 13 and does not knowingly collect personal information from them.

Security

All communication between the app, the web portal, and our server uses HTTPS (TLS). Passwords are stored only as salted hashes. Data on your device is protected by your device's own security — we recommend a passcode and up-to-date software.

Changes to this policy

We may update this policy as the app evolves. Material changes will be reflected here with a new “last updated” date.

Contact

Questions about this policy? Email [email protected].

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