Privacy policy for Cantela
Last updated: 30 September 2026
Cantela is a personal library app. This policy says what it does with your information, which is very little, and where that information lives, which is on your phone.
There is no account
You do not sign up, sign in, or give us an email address. There is nothing to reset and nothing to delete on a server, because there is no server that holds anything about you.
Your library lives on your phone
The books you add, the dates you read them, what stuck with you, your ratings, your notes and quotes, the threads you add or hide, the authors you block, your positions on the web, and your themes, frames and badges are stored in a database on your device. They are not sent to us. If you delete the app, they are deleted with it, unless your phone's own backup has kept a copy: Android's backup to your Google account, or iCloud on an iPhone, can hold them and bring them back when you reinstall. That copy is kept by Google or Apple under their terms, not by us. If you import a Goodreads or StoryGraph export, the file is read on your phone and is not uploaded anywhere.
The book library ships inside the app
The library of books, themes and connections is bundled with the app. Looking up a book in it does not leave your phone.
Open Library
The bundled library does not carry real covers or synopses. When you open a book's page, or look closely at a book the app suggests, the app asks Open Library (openlibrary.org, run by the Internet Archive) for that book's cover and description, and keeps the cover on your phone so it is asked for once. When you search for a book the bundled library does not have, the app asks Open Library for it. When you scan a barcode the bundled library does not recognise, the app sends Open Library that barcode's number.
In each case Open Library receives the title, author or number being looked up and your phone's network address, as any website you visit does. It is not told who you are or what else is in your library. Their policy is at archive.org/about/terms.php.
The camera
The app uses the camera only when you choose to: to scan a book's barcode, or to photograph a page and keep its words as a quote. A barcode's number is read on your phone. A photographed page is read on your phone too, by Google's ML Kit text recognition, which runs on the device; the photograph is not kept once its words are read, and neither the photograph nor the words are sent anywhere. The app does not use the microphone. You can refuse the permission and add books by searching, and type a quote instead.
Classifying a book you add
If you add a book the bundled library has never seen, the app sends that book's title, authors, year, language and public description to our own small service, which classifies it into the app's themes so it can join your web. That service receives the book, not you: no account, no device identifier, and nothing about the rest of your library. The classification is kept by the service so the same book is never classified twice, and it is shared with every copy of the app, because a book's themes are about the book.
Library updates
From time to time the app asks the same service which books have been classified since it last asked, and receives those books' themes. The request carries a date and, like any request over the internet, your phone's network address, and nothing about you or your library.
Links to Amazon and to Goodreads
A book's page can offer links to Amazon (the print edition, the Kindle edition and the Audible audiobook) and to the book's page on Goodreads. These open in your browser, outside the app. The link tells Amazon which book you are looking for, and carries our Amazon Associates code, so Amazon knows the visit came from this app and may pay us a small commission if you buy. We are not told who you are, what you bought, or whether you bought anything. Once you are on Amazon's site, its own privacy policy applies.
As an Amazon Associate we earn from qualifying purchases.
Sharing a card
The year card is drawn on your phone. It goes only where you send it, through your phone's own share sheet, and we never see it.
Crash reports
If the app crashes, a report of the crash (what the app was doing, the device model and system version, the app version) is sent to Sentry so the crash can be fixed. Crash reports do not include your library, your notes, or anything that identifies you. There is no other analytics, and no tracking of any kind.
Purchases
Premium (monthly, yearly or for good) and some skies are bought through the App Store or Google Play. Apple or Google handle the payment, hold your payment details and manage any subscription; the app never sees your payment details. The app keeps a record on your phone of what you have unlocked so it stays unlocked. RevenueCat, which the app uses to talk to both stores, receives an anonymous app-installation identifier and your purchase history for this app, and nothing else about you.
Children
The app is suitable for all ages and collects no personal information from anyone, including children.
Changes
If any of this changes, this policy will change first, and the date at the top will say when.