Litmus ("Litmus", "we", "us", or "our") is a reading tracker with social and diversity-aware features. This policy explains what information we collect, how we use it, and the choices you have. By using Litmus at litmusbooksapp.com or via an installed version of the app, you agree to this policy.
Litmus is an independently operated application. You can reach the operator at litmus.admin@litmusbooksapp.com for any privacy request.
Information we collect
Account information: the email address you sign in with (including via Google sign-in, if you use it).
Profile information: your username, optional display name, bio, profile and cover photos, profile customization, and your privacy settings.
Reading data: the books you add and their details, your shelves, ratings, reviews, notes, reading sessions, reading streaks, goals, and the diversity tags and scores derived from your library.
Social data: who you follow and who follows you, club memberships and posts, chat messages, wall and guestbook comments, and likes.
Notifications: records of activity directed at you (new followers, club joins, likes, wall posts) so we can show your notifications.
Technical data: standard information your browser or device sends when you use a website, such as IP address and device or browser type, primarily through our hosting providers' logs.
How we use your information
To provide Litmus: storing your library, tracking streaks and stats, and powering social features like clubs, following, and chat.
To generate book recommendations, including diversity-aware suggestions.
To show you notifications about activity directed at you.
To maintain security, prevent abuse, and operate and improve the service.
Litmus does not show ads and we do not sell your personal information.
How your information is shared
With other users: content you make public, such as your profile, reviews, lists, club posts, chat, and comments, is visible to others according to your privacy settings. You control much of this in Settings (for example, making your profile private).
With service providers: we use the third-party services listed below to operate Litmus. They process data on our behalf to deliver the service.
For legal reasons: we may disclose information if required by law or to protect the safety, rights, or property of users or the public.
Third-party services we use
Supabase — hosts our database, authentication, and file storage (where your account, reading, social data, and uploaded photos are stored).
Google Books API — used to look up book details and cover images when you add or search for books.
Google (Gemini) AI — when you request recommendations, relevant reading information may be sent to Google's Gemini API to generate suggestions.
Google Sign-In — if you choose to sign in with Google, Google handles authentication.
Vercel — hosts and serves the application.
Each provider handles data under its own privacy terms.
Data retention and deletion
We keep your information while your account is active. You can delete your account and associated data at any time from within the app (Settings, then Delete account), or by emailing litmus.admin@litmusbooksapp.com. See our data deletion page for details on what is removed and how to request it.
Your choices and rights
Access and export: you can export your data from Settings ("Download my data").
Correction: you can edit your profile, reviews, and library at any time.
Privacy controls: you can make your profile private and adjust what is shared in Settings.
Deletion: you can delete your account and data as described above.
Depending on where you live, you may have additional rights under laws such as PIPEDA, the GDPR, or the CCPA. To exercise any right, contact us at the email above.
Children's privacy
Litmus is not directed to children under 13 (or the minimum age of digital consent in your country, if higher), and we do not knowingly collect personal information from them. If you believe a child has provided us information, contact us and we will delete it.
Security
We use industry-standard measures to protect your data, including encrypted connections (HTTPS) and database access controls. No method of transmission or storage is perfectly secure, but we work to protect your information.
International users
Litmus is operated from Canada and our service providers may process and store data in other countries. By using Litmus, you understand your information may be processed outside your country of residence.
Changes to this policy
We may update this policy from time to time. When we make material changes, we will update the "Last updated" date above and, where appropriate, notify you in the app.