ShelfMark™
Privacy Policy

Last Updated: November 8, 2026
Effective Date: February 21, 2026

Son of a Good Man LLC (“Company,” “we,” “our,” or “us”) operates the ShelfMark: Book Catalog mobile and web application (“ShelfMark,” the “App” or “Service”).

This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use ShelfMark.

By using the App, you agree to the practices described in this Privacy Policy.

1. Information We Collect

We collect information in the following categories.

1.1 Information You Provide

When you create an account or use ShelfMark, you may provide:

  • Name (if provided)
  • Email address
  • Account credentials
  • Profile information
  • Book library data
  • Borrower details you enter when you lend a book: their name and, if you add them, their phone number and email. Only you can see them, and they are deleted with your account. Please add someone’s details only with their permission.
  • Reading progress and notes
  • Reviews and user-generated content
  • Support messages or feedback
  • Photos or images you upload (including book scans)

You may choose not to provide certain information, but some features may not function properly.

1.2 Information Collected Automatically

When you use the App, we may automatically collect:

  • Device type
  • Operating system
  • App version
  • IP address
  • Your device’s push notification token, if you allow notifications
  • Crash logs and performance data
  • App update checks: when the ShelfMark iOS app opens, it asks Expo whether a newer version of the app’s code is available (see section 3.1)

ShelfMark does not collect your location.

1.3 Analytics

ShelfMark sends anonymous usage counts, such as which features and screens are used, to PostHog, Inc., an analytics provider in the United States, so we can see what works and improve it. The app asks before sending any. If you say yes, you can turn it off at any time with the switch in the app’s Account → Privacy settings. When it is off, the app sends no usage counts.

  • Usage counts use a random identifier that is not linked to your account.
  • They never include the text of your books, notes or reviews, names, or email addresses.
  • There are no session recordings.
  • PostHog does not look up your location from your IP address.

1.4 How ShelfMark Uses AI

ShelfMark uses OpenAI to power its smart features. Our servers (never your device directly) send OpenAI only what each feature needs:

  • Photos you take: a photo of your shelf, to recognize the books in it. Only when you take or choose the photo.
  • Your reading life: the titles, authors and genres in your library, your ratings, reviews and notes, how you got a book, books you did not finish, and suggestions you dismissed, so we can recommend books that match what you love.
  • Friend picks: when you ask for picks from a friend’s library, their titles and genres are included, and their ratings only if they have chosen to share ratings. A friend’s Private library is never used.
  • What you search for: what you type into More like… (a book, show, film or genre you loved), to find similar books. Only after you allow it.
  • Book details: public information about a book (title, author, description), to write summaries, fill in missing details, list the books in a series, and write a short author bio when Wikipedia has none.
  • Your series: for Premium readers who have turned on Personalized recommendations, the titles and authors in their library, to find which series their books belong to.

OpenAI processes this on our behalf only to return results to you. Under OpenAI’s terms for business use, it is not used to train OpenAI’s models and is deleted within 30 days.

Your choices are saved in your account so recommendations get better the more you use ShelfMark. That personalization is yours alone: we do not use your content to train any AI model, and other users never see it.

Keeping the community safe. Before text or a photo you share with other people is posted (notes, messages, borrow requests, your name and username, profile photos and photo-frame decorations), it is checked by OpenAI’s moderation service so content that breaks our community standards isn’t posted. The app asks your permission first; if you say no, nothing is sent and that content isn’t posted. Only that text or photo is sent, and OpenAI does not use it to train its models.

On the ShelfMark website, voice quotes are transcribed by your browser’s built-in speech recognition, not by us.

Your choices. “Personalized recommendations” is off until you turn it on, in Account → Privacy or when a screen first asks. While it is off, nothing from your library is sent to OpenAI for recommendations or series lookups, and recommendation screens show popular or general picks instead. You can turn it off again at any time in the same place. The app asks before your first shelf photo or More like… search is sent to OpenAI, and you can change either answer in the same place. Barcode scanning never uses AI.

1.5 Community Suggestions

“Readers who loved this also loved” suggestions and yearly community highlights come from anonymous, combined counts. A book pairing only appears when at least three readers share it, and no one can see who rated or read what. If your library is set to Private, your books are not included.

1.6 Subscription and Payment Information

Payments are processed by Apple (App Store) or Google (Google Play). We use RevenueCat to manage subscription status. We never receive or store your card number.

We may receive limited billing information such as subscription status, transaction identifiers and purchase history.

If you request a refund from Apple, we may share information about your use of purchased content (such as whether and how much you have used the features you paid for) with Apple so it can evaluate your request.

1.7 Sign-in Information

If you sign in with Apple or Google, we receive the basic profile information you authorize, such as your name and email address (or an Apple relay email).

1.8 Crash Reports and Performance Timings

If the App crashes or hits an error, it sends a report to Functional Software, Inc. (Sentry) so we can fix it. To keep the App fast, it also sends Sentry timings of how long certain things take, such as loading a screen or your library, for a sample of sessions. Both carry technical details such as your device model, operating system and app version, and your ShelfMark account ID so we can see whether a problem affects one person or many. They never include your email address, the contents of your library, notes or reviews, or your photos. We use them only to keep the App working and to improve it, never for advertising or to track you across other apps and websites. Sentry deletes them automatically within 90 days.

2. How We Use Your Information

We use collected information to:

  • Provide and operate ShelfMark
  • Create and manage your account
  • Sync and display your book library
  • Provide AI-powered features
  • Process subscriptions
  • Improve performance and reliability
  • Monitor and prevent fraud or abuse
  • Respond to support requests
  • Communicate service updates
  • Comply with legal obligations

We do not sell your personal information.

3. How We Share Information

We share information only in limited circumstances.

3.1 Service Providers

We share data only with vendors that help operate ShelfMark, and only what each needs:

  • Supabase: account, library and photo storage, and our servers
  • OpenAI: AI features, as described in section 1.4
  • RevenueCat: subscription management
  • Apple and Google: payments, sign-in, and on-device speech recognition
  • Sentry: crash reports and performance timings, as described in section 1.8
  • PostHog: anonymous usage counts, as described in section 1.3
  • Resend: sending emails, such as password resets and other sign-in emails, and alerts to us about reports
  • Expo (650 Industries, Inc.) and Apple Push Notification service: delivering the notifications you turn on. They receive your device’s push token and the notification text, which may include a friend’s name or a book title. Expo also delivers updates to the app’s code: each time the ShelfMark iOS app opens, it checks Expo’s update service (u.expo.dev). That request carries your device’s IP address, its platform, the app’s version and runtime version, and the update channel, never your account details or library.
  • Open Library, ISBNdb, Hardcover, Wikipedia and Project Gutenberg: looking up book details, series and covers. These lookups contain only the title, author or ISBN being searched, never your name, email or library.

These providers process data only on our behalf, under contracts that require them to protect it at least as well as this policy does. We do not sell your personal information or use it for advertising.

3.2 Your Friends

Friends see only what your Account → Privacy settings allow: your library visibility (Public, Friends only or Private) and whether your ratings and shelf names are shown.

3.3 Legal Requirements

We may disclose information if required to:

  • comply with law
  • respond to legal process
  • protect our rights
  • investigate fraud or abuse
  • protect user safety

3.4 Business Transfers

If Son of a Good Man LLC undergoes a merger, acquisition, or asset sale, user information may be transferred as part of that transaction.

4. Data Retention

We retain personal information only as long as reasonably necessary to:

  • provide the Service
  • comply with legal obligations
  • resolve disputes
  • enforce agreements

You can delete your account in the app (Account → Delete account). That removes your library, photos and profile, ends any purchased AI credits, and disconnects Sign in with Apple. If you signed in with Google, you can also remove ShelfMark from the third-party connections in your Google Account. Remaining copies in backups are removed as backups expire (within 7 days), except where retention is legally required.

Photos you share. Profile photos and photos in photo-frame decorations are stored so friends can see them, at web addresses that are hard to guess but not password-protected: anyone given the exact address could open it.

5. Data Security

We implement reasonable administrative, technical, and organizational safeguards designed to protect your information.

However, no system is completely secure, and we cannot guarantee absolute security.

6. Your Privacy Rights

Depending on your location (including California), you may have rights to:

  • request access to your personal information
  • request deletion of your data
  • request correction of inaccurate data
  • object to certain processing
  • turn off personalized AI recommendations at any time (see section 1.4)
  • withdraw consent at any time: turn off Personalized recommendations or shelf-photo AI in Account → Privacy, turn off notifications in your phone’s Settings, or delete your account in Account → Delete account

To exercise your rights, contact us at support@sonofagoodman.com

We will respond in accordance with applicable law.

7. California Privacy Rights (CCPA/CPRA)

California residents have the right to:

  • Know what personal information we collect
  • Request deletion of personal information
  • Correct inaccurate personal information
  • Opt out of sale or sharing (we do not sell data)
  • Limit use of sensitive personal information (if applicable)

To submit a California privacy request, email:

support@sonofagoodman.com

8. Children’s Privacy

ShelfMark is not directed to children under 13.

We do not knowingly collect personal information from children under 13. If we learn that we have done so, we will delete the information promptly.

9. International Users

ShelfMark is operated in the United States.

If you access the App from outside the U.S., your information may be transferred to and processed in the United States, which may have different data protection laws.

10. Third-Party Links

ShelfMark may contain links to external websites (such as retailers or publishers). We are not responsible for the privacy practices of third parties.

11. Changes to This Privacy Policy

We may update this Privacy Policy from time to time.

When we do, we will update the Last Updated date. Continued use of ShelfMark after changes become effective constitutes acceptance of the revised policy.

12. Contact Us

If you have questions about this Privacy Policy or our data practices, contact:

Son of a Good Man LLC
435 E. Market St.
Long Beach, CA 90805
United States
Support: support@sonofagoodman.com

Version: 1.4