BookFly
Privacy policy
Almost nothing leaves your phone.
BookFly has no account, no login and no email address for you. Your library lives on your phone. This page says exactly what does leave it, when, and to whom.
What BookFly never collects
- No account. No email, no password, no username, no phone number. There is nothing to sign into.
- No advertising and no tracking. BookFly contains no advertising library and no crash reporter, and never asks for the identifier for advertisers. Nothing it collects is shared for advertising or linked with other companies' data to follow you across apps and websites. From version 1.1 it has one outside library, Adapty, which counts subscriptions: what Adapty gets is below. In the EU, the rest of the European Economic Area and the UK it is off until you agree, and anywhere you can turn it off.
- No location, contacts, calendar or health data. The app never asks for any of them.
- No payment details. Subscriptions are handled entirely by Apple. BookFly never sees your card, your name or your billing address.
Where your library lives
On your phone. Your books, reading states, finish dates, loans and notes are stored on the device and nowhere else. There is no BookFly account holding a copy, and no cloud sync.
That has a consequence worth stating plainly: if you lose the phone without exporting, the library is gone. Export writes a file you control, and it is the only copy that exists off the device. Nobody can recover it for you, because nobody else ever had it.
Deleting the app deletes the library with it.
What does leave your phone
Seven things, each for a stated purpose.
| What | Goes to | Why | When |
|---|---|---|---|
| The photograph of your shelf, or of one book | BookFly's server, then OpenAI | To read the spines or the cover and name the books | Only with a plan: shelf photographs after you tap Name these books, a One book photograph after you take it |
| Your App Store transaction | BookFly's server | To check the subscription is real before spending on the model | With each paid request |
| Titles and authors of recommended books | Open Library | To confirm a recommended book exists, and to find its cover while Book covers is on | Only while recommendations are being chosen |
| The title and author of each book in your library | Open Library | To find the book's cover | While Book covers is on in Settings, which it is unless you turn it off: once for each book, and again only if you change its title or author |
| A list of your books | BookFly's server, then OpenAI | To suggest what to read next | Only with a plan, after you have opened Picks, when this week's picks have not been fetched yet; or when you tap Try again there. The weekly notification sends nothing; tapping it opens Picks |
| Your conversation in Chat and a list of your books | BookFly's server, then OpenAI | To answer questions about your shelves. Your newest message and each reply are also checked by OpenAI's moderation service, so Chat keeps to books and holds back harmful replies | Only with BookFly + Chat, each time you send a message in Chat |
| A Chat reply you report, and your message just before it | BookFly's server, where it is kept for 30 days and then deleted | So a person can read what went wrong and put it right | Only when you report a reply in Chat and confirm. Nothing else goes with it: no identifier of you or of your phone |
| Your purchases, which wording of the subscription page you saw, when you open BookFly, and details of the phone | Adapty | To count subscriptions, and to learn which wording of the subscription page works better | From version 1.1, while Share subscription statistics is on in Settings. In the EU, the rest of the European Economic Area and the UK it is off until you say yes when BookFly asks; elsewhere it is on unless you turn it off, and a phone that had an earlier version is told first. Details below |
Counting is free, and it never leaves the phone
The count you see before you are asked to pay is produced entirely on the device. No photograph is uploaded to produce it. If you look at the number and close the app, nothing was sent anywhere.
Nothing goes to OpenAI until you agree
The first time BookFly is about to send a photograph to be named, a list of your books for Picks, or a message in Chat, it says what goes to OpenAI, BookFly's AI partner, and sends nothing until you tap Agree and continue. To take that back, turn off Send to AI partner (Send to OpenAI in version 1.0) in Settings, under Privacy; each of the three then asks again before it sends anything.
The photographs
With a plan, a shelf photograph is sent when you tap Name these books, and a photograph of one book as soon as you take it. It passes through BookFly's server to OpenAI, which reads it and returns titles and authors.
- BookFly's server does not store your photographs. It holds the image in memory for the length of the request and writes none of it to disk. There is no database.
- OpenAI does not use API data to train its models. Under its API terms, content sent through the API is excluded from training by default. Its terms let it keep that content for up to 30 days to check for abuse, and longer only where the law requires it or to prevent harm. Their policy is at openai.com/policies.
- Photographs are never shown to anyone, published, or shared with any other party.
What the server keeps
BookFly's server exists so that an API key does not have to be shipped inside an app, where anybody could extract it. It is deliberately forgetful.
- No database, and nothing written to disk except a Chat reply you report (above).
- One identifier, in memory only. Apple issues a subscription identifier with each transaction. The server counts requests against it so that one subscription cannot be used to run up an unlimited bill. It is not linked to your name, email or device, it is discarded when the process restarts, and it is swept periodically.
- Logs of what happened, never of what was said. Each request's size, timing and cost is logged, and so is any failure. Your photographs, your messages and your book list are not. When moderation flags a message, the kind of flag is logged, never the words.
Open Library
BookFly asks Open Library, a public catalogue run by the Internet Archive, two things: whether a recommended book exists, and which cover goes with each recommended book and each book in your library. Each question carries one title and one author, and no account, identifier or cookie; like every request on the internet, it also carries your phone's internet address. They are made directly by your phone.
A cover picture is then fetched from Open Library by its number, and kept on your phone. Covers are never uploaded anywhere and are not in the backup; a new phone fetches its own.
To stop it, turn off Book covers in Settings, under Library. With it off, no title from your library is sent to Open Library and no cover is fetched, for your books or for your picks.
Adapty
From version 1.1, BookFly includes Adapty, a library that counts subscriptions and shows different wording on the page that sells them to different people, to learn which works better. Apple still takes every payment, and BookFly's server still checks each subscription itself: nothing you have paid for depends on Adapty.
What Adapty receives from your phone:
- Your purchases: each App Store purchase, renewal and refund BookFly sees, with its plan, price, dates and Apple's numbers for it.
- The subscription page: which wording you were given, when the page was shown, and which wording a purchase was made from.
- When you open BookFly, a check of its own record every minute or so while the app is open, and notes of what the library itself did, such as fetching the page's wording, which Adapty uses to find faults in it.
- Details of the phone: its model, iOS version, language, time zone and App Store country, BookFly's version, a random identifier for this installation of BookFly, and the identifier Apple gives one developer's apps on one phone, which is the same in all of that developer's apps and different for every other developer.
In the EU, the rest of the European Economic Area and the UK, BookFly asks first. Nothing goes to Adapty from your phone until you tap Share statistics. Do not share, the same kind of button under it, is just as easy, and with it BookFly never starts Adapty. BookFly counts a phone as there when its region setting or its App Store country is one of those places, and asks too when it cannot tell. Elsewhere Adapty is on unless you turn it off, and somebody updating from an earlier version is told before it starts.
It never receives your books, your photographs, your lists or your messages, or anything else about your library. BookFly has no name or email address to give it. BookFly tells Adapty not to read the identifier for advertisers, not to keep your IP address (like any server, Adapty's sees the address a request comes from), and not to attribute installs to advertising.
At BookFly's request, Apple also tells Adapty directly about changes to subscriptions to BookFly, such as when one starts, renews, fails to renew, ends or is refunded. Those notices come from Apple, not from your phone, so neither your answer nor the switch below stops them. They carry details of the subscription, such as its plan, dates, price and country, and Apple's numbers for it, but no name, email address or card details.
Adapty handles all of this for BookFly as its data processor, under the data processing agreement that is part of Adapty's terms. That agreement lets Adapty use it only to provide its service to BookFly or where the law requires it, forbids selling it, requires Adapty to keep it secure and confidential, and requires any company Adapty uses to handle it to give it at least the same protection. It sets no fixed period: Adapty keeps it while BookFly uses Adapty, and deletes it or returns it to BookFly when BookFly stops or asks, apart from copies the law makes it keep for a time, backups until they are overwritten, and information made anonymous so that it identifies nobody. Its policy for people who use apps built with it is at adapty.io/end-users-privacy.
To stop it, turn off Share subscription statistics in Settings, under Privacy. BookFly then tells Adapty nothing more, at once. Adapty itself cannot be stopped once it has started, so its own upkeep, the notes of opening and the checks above, which carry no purchases, goes on until BookFly is next fully closed, and it is not started again after that.
The companies named here
OpenAI and Adapty handle what they receive for BookFly under terms that bind them to BookFly. Each may use it only to provide its service to BookFly, where the law requires it, and, for OpenAI, to enforce its policies and prevent abuse; each must keep it secure and confidential. Under those terms, both protect your data at least as well as this page describes.
Open Library is a public catalogue that anyone can use, and BookFly has no separate agreement with it: the Internet Archive's own policy, at archive.org/about/terms.php, covers the requests your phone makes to it. To send it no title from your library, turn off Book covers (above).
Children
BookFly is not directed at children. It asks nobody for a name, an email address or any other contact details, and what it sends, set out above, is the same for everybody.
Your rights, and how little there is to exercise them on
Most privacy rights concern data a company holds about you. BookFly itself holds none: no account, no profile, no history, and a server that keeps nothing. From version 1.1, Adapty keeps the record described above for BookFly, under a random identifier for each installation and under no name.
- To see your data, open the app. It is all there, and Export writes it to a file you keep.
- To delete it, delete the app, or remove books individually. To have Adapty's record deleted too, write to the address below and BookFly will ask Adapty to delete it.
- To stop everything leaving the phone, turn off Book covers, Send to AI partner (Send to OpenAI in version 1.0) and Share subscription statistics (from version 1.1) in Settings, and do not name books from a photograph, open Picks or send a message in Chat. Counting, browsing, editing, lending and exporting all work with no network at all.
If you believe there is something held about you and you want it removed, write to the address below and it will be handled.
Changes
If this policy changes in a way that affects what leaves your phone, the app will say so before it happens rather than quietly updating this page.