Privacy Policy

Last Updated: June 29, 2026

1. Introduction

BookBridge ("we," "us," or "our") is committed to protecting your privacy and ensuring a transparent, secure environment for digital library syncing. This Privacy Policy describes how we collect, use, store, and share personal data collected from users ("you" or "your") who download our mobile application (the "App"), visit bookbridge.top (the "Site"), or use our library formatting and dispatch services (collectively, the "Services").

By accessing or using the Services, you acknowledge that you have read and understood this Privacy Policy. If you do not agree with the terms outlined here, please refrain from downloading the App or utilizing our sync platforms.

2. Information We Collect

We collect only the minimum amount of information required to deliver a reliable, secure sync pipeline. The data we collect falls into three main categories:

A. Information You Actively Provide:

  • Account Details: When you register an account, we collect your email address, chosen name, and encrypted account credentials.
  • Reader Configurations: To support wireless syncing, you provide your destination e-reader email address (e.g., your Amazon @kindle.com address).
  • Support Inquiries: When you contact us using the Support form or email, we collect your name, email, topic, and the contents of your message.

B. Information Collected Automatically:

  • Device & Application Data: We collect device-specific info, including hardware model, operating system version (iOS/Android), application version, and system language settings.
  • Uptime & Failure Diagnostics: To resolve sync glitches, we log diagnostic events, sync failure reports, and memory usage states. These logs do not contain raw text of your files.
  • IP Addresses & Connection Logs: We log connection IP addresses and connection metadata solely for system protection and rate-limiting enforcement.

C. Document Handling & Temporary Storage:

  • Book Metadata: To curate your shelves, we index basic book details (titles, author names, category tags, page sizes, and cover thumbnail blocks).
  • In-Memory File Processing: When you click "Send to Kindle," your EPUB or PDF file is uploaded to our secure servers. The file is parsed and transmitted using SSL/TLS. Crucially, files are processed entirely in-memory and are permanently deleted from our cache folders immediately upon successful dispatch to Amazon's servers. We do not keep permanent archives of your personal library files on our cloud servers.

3. How We Use Your Information

We use your personal data to run, secure, and refine the BookBridge platform. Specifically, we use your data to:

  • Provision, operate, and maintain your account;
  • Execute metadata parsing and wireless document dispatch services (e.g., Send to Kindle);
  • Manage subscription billing, process payments, and prevent transaction fraud;
  • Provide user assistance, troubleshoot bugs, and respond to your messages;
  • Protect our server infrastructure against DDoS attacks, scraping, and service exploitation;
  • Verify compliance with our Terms of Service and legal obligations.

4. Cookies & Local Storage

BookBridge uses local storage containers (like standard browser cookies, LocalStorage, and iOS Keychain) to enhance security and ease of use. These items serve the following purposes:

  • Authentication: Keeping your session active without requiring log-in every time you launch the App.
  • Security Credentials: Encrypting and caching custom OPDS feed keys and passwords within your local system Keychain.
  • Preferences: Saving theme configurations (e.g. font sizes, reading progress categories, dark mode).

You can adjust your mobile device or browser settings to block or delete cookies, though this may prevent certain features of our Service from operating correctly.

5. Data Sharing & Third-Party Disclosures

We do not sell, rent, or lease your personal data or reading lists to advertising networks, data brokers, or third-party market analytical firms. We only share information with partners and contractors who perform functions vital to our Service:

  • Amazon Kindle Services: To deliver books wirelessly, we transmit files and metadata to Amazon's Personal Document Delivery email servers. This delivery is governed under Amazon's Privacy Policy.
  • Payment Processors: Recurring subscription payments are securely processed by Stripe or Apple App Store. Stripe processes your financial details under its own privacy policies.
  • Cloud Infrastructure Hosts: Our server environments and databases are hosted on secured clouds (such as Amazon Web Services or Google Cloud Platform). They provide physical and logical network security.
  • Legal Compliance: We may disclose data if legally required to do so under subpoena, court order, or search warrant, or to protect the safety, properties, and rights of BookBridge and our users.

6. Data Security Measures

We implement robust, industry-standard security measures to safeguard your information:

  • Transport Encryption: All communications between the App, our servers, and third-party APIs are encrypted using HTTPS (SSL/TLS protocols) in transit.
  • Credential Hashing: Passwords and API secrets are protected using salt-based hashing functions.
  • Strict Memory Purging: Files uploaded for Kindle syncing are held only in short-term RAM or temporary cached folders and are purged as soon as transmission succeeds or fails.

However, please be aware that no storage system or internet data transmission method can be guaranteed 100% secure. You are responsible for maintaining the safety of your password and securing your device.

7. Data Retention Cycles

We retain your personal details (such as account credentials, metadata, and Kindle settings) for as long as your account remains active. If you request account deletion, we will immediately initiate the deletion process.

Upon deletion, all records, logs, configuration preferences, and indexed metadata associated with your account are permanently erased from our active databases within 48 hours, and fully purged from rolling backups within 30 days. Contact and support emails are archived for up to 12 months to handle follow-up inquiries before being deleted.

8. International Data Transfers

BookBridge operates servers primarily in the United States. If you are accessing our Services from the European Economic Area (EEA), United Kingdom (UK), or other global regions with distinct data protection laws, please note that your data will be transferred to, stored, and processed in the United States.

When transferring data outside the EEA or UK, we rely on Standard Contractual Clauses (SCCs) approved by the European Commission, ensuring your personal information receives a level of protection comparable to GDPR guidelines.

9. Your Privacy Rights

Depending on your jurisdiction (such as California under the CCPA/CPRA, or the EEA/UK under the GDPR), you hold several key rights regarding your personal information:

  • Right to Access: You can request a detailed report of the personal information we hold about you.
  • Right to Rectification: You can correct or update inaccurate account settings inside the App at any time.
  • Right to Erasure (Deletion): You can request that we purge all personal data and delete your account.
  • Right to Portability: You can request a copy of your personal data in a structured, machine-readable format.
  • Right to Object: You can object to the processing of your data based on legitimate business interests.

To exercise any of these rights, please contact us via the Support form or email us at privacy@bookbridge.top. We will verify your identity before processing the request. We do not discriminate against users for exercising their privacy rights.

10. Children's Privacy

BookBridge does not knowingly target, solicit, or collect personal data from children under 13 years of age (or under 16 years of age in certain European jurisdictions). If we become aware that we have inadvertently collected personal data from a child under the required consent age without parental authorization, we will take immediate steps to delete that data from our server records. If you believe a child has provided data to us, please notify us at privacy@bookbridge.top.

11. Changes to This Privacy Policy

We may update this Privacy Policy from time to time to reflect operational modifications, technical advancements, or regulatory shifts. We will publish the modified Privacy Policy on this page and revise the "Last Updated" date. If the changes are material, we will provide a prominent notification via the App or email. We encourage you to review this policy periodically to stay informed about how we safeguard your data.

12. Contact & Controller Details

If you have any questions, concerns, or requests regarding this Privacy Policy or our data management operations, please contact us via:

  • Data Controller: BookBridge App Operations
  • Email Address: privacy@bookbridge.top
  • Mailing Address: BookBridge Legal Department, 1209 North Orange Street, Wilmington, DE 19801, United States.