If this English version and the Turkish version differ, the Turkish version prevails.
BookFlip Privacy Policy
Effective date: 10 October 2026
Version: 1.1
BookFlip is a mobile app that lets middle and high school students catalogue the books they have at home, lend and borrow them among friends, and build a reading habit. Most of our users are under 18, so privacy is at the centre of the design: we collect only what the service genuinely needs, we show no ads, and we never sell data.
This policy covers the BookFlip iOS and Android apps and their server services. Detailed information under Turkey’s Personal Data Protection Law No. 6698 (“KVKK”) is also given in the KVKK Information Notice (Turkish).
1. In short
- We do not collect real names, schools, addresses, location, phone numbers or photos of users. Users have a nickname and a preset avatar.
- Users cannot search for or browse other users. Friendships are made only with a personal friend code or an invite link.
- There is no free-text chat. Users can only send the preset messages the app offers.
- Book photos are processed on the device and never uploaded. The app never accesses your contacts.
- For users under 18, friends, loans and messages stay switched off until a parent gives consent. Parental consent requires adding a parent’s email.
- We use no advertising, ad tracking or analytics tools. We do not sell or rent data.
- Our servers and backups are located in Istanbul, Türkiye.
2. Data controller and contact
Your personal data is processed by the BookFlip app as data controller. Send any privacy question or request to [email protected].
3. Age limit and children’s data
- BookFlip is not for children under 10. Sign-up asks only for the year of birth; sign-up cannot be completed by anyone who is under 10.
- A parent’s email is not required to sign up. Until a parent email is added and the parent consents, the child can use only their own library and personal reading goals, streaks and badges. Adding friends, lending and borrowing, preset messages and reading challenges with friends are switched off; the child cannot interact with any other user and no other user can see them.
- A parent’s email (parent or legal guardian) can be added during sign-up or later in Profile. When it is, we email the parent an explanation of what data is processed and a consent link (Parental Consent). Once the parent consents, the social features open.
- When the parent consents, we record the time and the version of the text approved. A parent email that is not confirmed within 7 days is deleted; the child’s account continues for personal use and a new parent email can be added.
- A parent who has consented can withdraw consent, freeze the child’s account or have it permanently deleted at any time, via the link in the weekly email or by writing to us. Even if no parent email was added, a parent can write to [email protected] about their child’s account.
- Parents who have consented receive a weekly summary email with the child’s reading statistics (books finished, reading streak, goal progress, badges earned) and a summary of loans. It never contains message content or details identifying the child’s friends.
- We do not show ads to children, profile them or target them based on behaviour.
4. Data we process
| Category | Examples | Source |
|---|---|---|
| Account | Nickname, chosen preset avatar, year of birth, email address, password (stored only as an irreversible hash) | User |
| Parent | Parent email address, time of consent, version of the consent text, IP address at the time of consent | User and parent |
| Friends | Personal friend code, friend requests and their status, invite links and their use, blocks | App and user |
| Library | Books added (title, author, publisher, ISBN, cover image, etc.), condition, the user’s note, shelf tags, “lendable” setting | User, barcode and open book databases |
| Loans | Who asked whom for which book, request, handover and return dates, condition recorded on return (new / good / worn), confirmations by both sides | Users |
| Preset messages | Sender, recipient, chosen preset message, related loan, sent and read times | Users |
| Reading motivation | Reading goals, streaks, finished books, badges, reading challenges with friends | User and app |
| Reports | The user, book entry or loan reported, the reason chosen, an optional description, and the nickname, avatar, book and loan details at the time of the report | The reporting user and the app |
| Moderation records | Warnings, restrictions, nickname change history, audit records of account actions | Moderators and user |
| Security logs | IP address, port, date and time, device/app information and the type of action (sign-up, sign-in, nickname change, adding a book, friend request, invite, report and so on) | Device and server |
| App installation ID | A random number generated by the app (not an advertising ID), used to stop spam accounts and closed accounts from being reopened | App |
| Device and notifications | Push token, platform (iOS/Android), last seen time, app version | Device |
| Technical logs | IP address, request time, requested path, error codes (server logs) | Device and server |
We do not process: real names, school names, addresses, location, phone numbers, user photos, contact lists, free-text messages, or special categories of data such as health, religion or ethnicity.
Camera, photos and invites
- Barcode scanning and cover / imprint page photos are processed only on your device (Apple Vision on iOS, Google ML Kit on-device models on Android). Photos are never sent to our server; only the extracted book details (title, author, ISBN and so on) are saved after you confirm them. On Android, ML Kit sends Google diagnostic and usage metrics that contain no photos or text (see section 8).
- Invites: the app does not access your contacts. To invite a friend you send the invite link yourself through your phone’s share menu (WhatsApp, SMS and so on).
5. Purposes and legal bases
| Purpose | Legal basis under KVKK |
|---|---|
| Creating an account, signing in, protecting the account | Performance of a contract (art. 5/2-c) |
| Obtaining and proving parental consent when a parent email is added | Parent’s explicit consent (art. 5/1); keeping the consent record to establish, exercise or defend rights (art. 5/2-e) |
| Library and personal reading features | Performance of a contract (art. 5/2-c) |
| Opening friends, loans, preset messages and challenges for users under 18 | Parent’s explicit consent (art. 5/1); for users 18 and over, performance of a contract (art. 5/2-c) |
| Reading goals, streaks, badges and challenges | Performance of a contract (art. 5/2-c) |
| Sending push notifications | Performance of a contract (art. 5/2-c); the notification permission on your device |
| Weekly summary email to parents | Parent’s explicit consent (art. 5/1) |
| Looking up book details from a barcode | Performance of a contract (art. 5/2-c). Only the ISBN is sent to external book databases, no personal data. |
| Automatically checking nicknames and book details, handling reports, blocking, and enforcing the community rules | Performance of a contract (art. 5/2-c) and legitimate interest (art. 5/2-f) |
| Keeping records of serious safety incidents and reporting them to authorities | Legal obligation (art. 5/2-ç) and establishing, exercising or defending rights (art. 5/2-e) |
| Keeping traffic data (IP address, date and time, action) | Required by Law No. 5651 and legal obligation (art. 5/2-a and 5/2-ç) |
| Finding bugs and keeping the service secure and running | Legitimate interest (art. 5/2-f) |
| Meeting legal obligations and lawful requests by authorities | Required by law and legal obligation (art. 5/2-a and 5/2-ç) |
We do not use your data for advertising, marketing, profiling or automated decision-making.
6. What other users can see
- People who are not your friends cannot see you, find you or get any information about you.
- Friends you have accepted see, on your friend profile, your nickname, avatar, badges earned, lendable shelf and reading summary (number of books finished, reading streak, this month’s numbers). You can turn the reading summary off in Profile settings (it is on by default). Your notes, page logs, reading goals and full library are never shown to friends. Friends also see the loans between you and the preset messages you send each other; friends taking part in a reading challenge with you see your progress in that challenge.
- There are no public rankings or leaderboards.
- Your email, year of birth and parent details are never shown to other users.
- People you report or block are not told. If several people report your nickname as inappropriate, other users may see “Reader” instead of your nickname until the review is finished.
7. Safety, reports and moderation
To keep BookFlip safe for children:
- Nicknames and manually entered book details are checked automatically on our server when saved. Nicknames containing swearing, inappropriate words, personal information (phone, email, school, first and last name and so on) or that impersonate the BookFlip team or an organisation are not accepted. This check looks only at the text entered; it does not build a profile of you and never leads to a sanction on its own. Any sanction (warning, restriction, suspension, closure) is always decided by a person on our team.
- Blocking: when you block a user, you cannot see each other or send requests and messages. The blocked person is not notified.
- Reporting: you can report a user, a book entry or a loan in the app. Only the BookFlip moderation team sees reports; the person you report is never shown your name or your description. For the review we keep a copy of the relevant details at the time of the report (nickname, avatar, book and loan details, preset messages between you), so the report can be assessed even if they change later.
- Informing parents: we email a parent who has consented when their child makes a serious safety report (the child can turn this off on the report screen) and when their child is restricted, suspended or closed. These emails never identify the other child.
- Authorities: if there are signs that a child’s safety is in serious danger or that a crime has been committed, we keep the relevant records and share them with the competent authorities when required by law.
- Moderation team: reports are reviewed only by authorised BookFlip moderators who sign in with two-step verification and whose every action is logged. No services located abroad are used for moderation.
Our rules and the steps we take: Community Rules (Turkish, with an English summary).
8. Who we share data with
We do not sell, rent or share data for advertising. To run the service we share only what is necessary with these providers:
| Recipient | What | Why | Location |
|---|---|---|---|
| Friends you have accepted (in the app) | Nickname, avatar, badges, lendable shelf, reading summary (can be turned off), loans between you and preset messages; details in section 6 | Friend profile, loans and messages | In the app |
| Parent who has consented | That the child made a serious safety report; a restriction, suspension or closure applied to the child and the reason | Protecting the child | Email (Google Workspace, abroad) |
| Server hosting provider (Bilhost) | All service data (server rental) | Running the app | Türkiye (Istanbul) |
| Apple Push Notification service (Apple Inc.) | iOS push token and a generic notification text | Delivering notifications to iOS devices | Abroad (USA) |
| Firebase Cloud Messaging (Google LLC) | Android push token and a generic notification text | Delivering notifications to Android devices | Abroad (USA) |
| Google ML Kit (Google LLC), Android only | Diagnostic and usage metrics without photos, text or user ID (device model, OS, app version, performance) | Running and improving the on-device barcode and text recognition models | Abroad |
| Google Workspace email (Google LLC) | User and parent email addresses, content of consent, password reset and weekly summary emails | Sending email | Abroad |
| Open book databases (Google Books, Open Library) | From our server, ISBN only (not personal data) | Looking up book details | Abroad |
| Cover image servers (Google Books, Open Library) | Your device’s IP address when a cover image is shown in the app | Showing book covers | Abroad |
| Competent public authorities and courts | Data that is lawfully requested | Legal obligation | Türkiye |
Notification texts are deliberately generic (for example “You have a new loan request”). They never include nicknames, book titles or message content.
International transfers
Our main database and backups are in Türkiye. The limited transfers to the services marked “abroad” above are made in line with the conditions of article 9 of KVKK.
9. Retention
| Data | Retention |
|---|---|
| Account, library, friend, loan, message and reading data | While the account is open. Deleted or anonymised within 30 days after the account is deleted. |
| Unconfirmed parent email address | 7 days after it was added |
| Parental consent record | For the life of the account and 3 years after deletion, as proof |
| Reports and moderation records (report details and snapshot, warnings and restrictions) | 2 years after closure, then stripped of identifying details |
| Report description (free text) | 6 months after the report is closed |
| Nickname history | 1 year |
| Push tokens | Deleted on sign-out, app removal or when the token becomes invalid |
| Security logs and server access logs (IP address, date and time, action) | 1 year |
| Irreversible hash of a permanently closed account’s email address and installation ID | 2 years after closure (to stop the closed account from being reopened) |
| Records related to an incident under legal proceedings | Until the proceedings end |
| Backups | Encrypted, kept for 30 days, after which deleted data is gone from backups too |
After an account is deleted, loans that appear in another user’s history may remain under the label “Deleted user” so that the other user’s records stay intact, in a way that no longer identifies you. Even if you delete your account, the record of an open or closed report involving you and security logs are kept for the periods above and then deleted.
10. Security
- All traffic between the app and the server is encrypted with HTTPS (TLS).
- Passwords are stored only as a strong, irreversible hash (argon2).
- Friend codes are long enough not to be guessed, and the number of attempts is limited.
- A user’s friend profile and lendable shelf are visible only to accepted friends, and this rule is enforced on the server.
- The database is reachable only from the server’s internal network, backups are encrypted, and administrator access is limited and logged.
- The moderation panel can be reached only from specific networks with two-step verification; moderators see email addresses masked by default and every action in the panel is logged.
No system is free of risk. If a data breach happens, we will notify the Turkish Personal Data Protection Board and affected users (and their parents, if a parent email was confirmed) as required by KVKK.
11. Your rights (KVKK article 11)
You, or your parent if you are under 18, can ask us to:
- tell you whether your personal data is processed,
- give information about it if it is,
- tell you the purpose of processing and whether data is used for that purpose,
- tell you the third parties, in Türkiye or abroad, to whom data is transferred,
- correct incomplete or inaccurate data,
- delete or destroy data under the conditions of article 7 of KVKK,
- notify third parties to whom data was transferred of corrections or deletions,
- object to an outcome against you that arises solely from automated analysis,
- compensate damage caused by unlawful processing.
Easy ways: You can correct profile details in the app and delete your account permanently under Profile > Delete account. Parents who have consented can freeze or delete the account from the link in the weekly email.
Formal requests: Send your request to [email protected] (sending it from the email registered in BookFlip is enough for us to verify you). We answer free of charge within 30 days. If you are not satisfied, you may complain to the Turkish Personal Data Protection Board.
12. Withdrawing consent
Parental consent can be withdrawn at any time. When it is, friends, loans, messages and challenges are switched off, the weekly email stops and the parent email is deleted; if the parent wishes, the child’s account is also frozen or deleted entirely. Withdrawal does not affect processing done before it.
13. Account and data deletion
- In the app: Profile > Delete account.
- As a parent: the “Delete account” link in the weekly summary email, or an email to [email protected].
- Without access to the app: email [email protected] from your registered email address with the subject “Delete my account”.
The account is closed immediately, data is deleted from our servers within 30 days and from backups no later than 30 days after that. Records we must keep by law (section 9) are kept with restricted access for the stated period.
14. Ads, tracking and analytics
BookFlip has no ads. We do not collect advertising identifiers (IDFA / Android Advertising ID), do not track you across apps or websites, and do not use analytics or advertising SDKs. The one exception is the diagnostic metrics of Google ML Kit, used on Android for barcode and text recognition, described above; they are not used for advertising or profiling.
15. Changes
If we change this policy we will publish the new date on this page. We will announce significant changes in the app and by email to parents who have consented. If a change requires new consent, we will ask the parent again.
16. Contact
For any privacy question: [email protected]