Privacy Policy

Last updated: March 24, 2026

1. Introduction

Cinder ("we," "us," "our," or "the app") is an ebook reader application. We are committed to protecting your privacy and being transparent about how we handle your data. This Privacy Policy describes the information we collect, how we use it, and your rights.

By using Cinder, you consent to the practices described in this Privacy Policy. If you do not agree, please do not use the app.

2. Information We Collect

Cinder is designed with a privacy-first, account-free architecture. We collect only the minimum data necessary to operate the app:

2.1 Information Collected Automatically

• App Usage Data: Basic, non-identifying usage analytics may be collected by Apple (via App Store) or the device operating system. We do not operate our own analytics or tracking systems.

2.2 Information You Provide

• Library Metadata: Basic metadata about books in your library (titles, authors, genres) stored locally on your device.
• Reading Progress: Your current reading position and progress percentage for each book, stored locally on your device.
• User-Configured API Keys: If you add third-party addons, your API credentials are stored exclusively in your device's secure keychain and are never transmitted to us.
• Contact Information: If you voluntarily contact us through our contact form or email, we collect the information you provide (e.g., name, email address, message content).

3. Information We Do Not Collect

• Personal names, email addresses, or phone numbers (unless you voluntarily submit them via our contact form)
• Precise or approximate location data
• Browsing or search history outside the app
• Contacts, photos, camera, microphone, or other device sensor data
• Payment, financial, or credit card information
• Advertising identifiers (IDFA/GAID)
• Cross-app tracking data

4. How We Use Your Information

• To provide and maintain the app's core reading functionality
• To respond to contact form submissions or support requests
• To improve the app's functionality, performance, and user experience
• To comply with legal obligations

We do not use your information for advertising, profiling, or behavioral targeting.

5. Third-Party Services

Cinder interacts with the following third-party services to provide functionality:

• Apple Books / iTunes Search API: Used to discover and browse books. Search queries are sent directly to Apple's servers. Apple's Privacy Policy governs their data handling.
• Open Library API: Used as a supplementary book metadata and cover art source. Queries are sent directly to the Internet Archive's servers. Internet Archive's Terms apply.
• Project Gutenberg: Used to provide free public domain ebook downloads. Project Gutenberg's Terms apply.
• User-Configured Addons: If you add third-party metadata providers or download sources, those services will receive search queries and other data from the app as configured by you. We are not responsible for the privacy practices of user-configured third-party services. You should review the privacy policies of any third-party addon services before configuring them.

6. Data Storage and Security

• All book data, reading progress, and app settings are stored locally on your device.
• API keys and credentials are stored in your device's secure keychain, never in plain text or application storage.
• No data is sold, rented, shared with advertisers, or used for user profiling.
• We implement industry-standard security measures but cannot guarantee absolute security of data transmitted over the internet.

7. Data Retention and Deletion

Your local data is under your complete control:

• You can delete all app data at any time by uninstalling the app or clearing app data in your device settings.
• Contact form submissions are retained for up to 24 months for customer support purposes, then deleted.

8. Your Rights (GDPR / CCPA / Global)

Depending on your jurisdiction, you may have certain rights regarding your personal data:

• Right to Access: You may request a copy of any data we hold about you.
• Right to Deletion: You may request deletion of your data.
• Right to Rectification: You may request correction of inaccurate data.
• Right to Data Portability: You may request your data in a machine-readable format.
• Right to Object: You may object to certain types of data processing.
• Right to Opt-Out (California / CCPA): We do not sell personal information. California residents have additional rights under the CCPA.

Since Cinder does not require accounts and collects no personally identifiable information, most of these rights are satisfied by default. To exercise any of these rights, please contact us.

9. International Data Transfers

Cinder does not transmit your personal data to our servers. However, when you use built-in features (such as book discovery), search queries are sent directly from your device to third-party APIs (Apple, Open Library, Project Gutenberg) which may be hosted in different countries. By using these features, you consent to such transfers as governed by each service's own privacy policy.

10. Children's Privacy

Cinder is not directed at children under the age of 13 (or the applicable age in your jurisdiction). We do not knowingly collect personal information from children. If you believe a child has provided personal information to us, please contact us and we will promptly delete such information.

11. Do Not Track Signals

Cinder does not track users across third-party websites or services. We honor Do Not Track (DNT) signals by default, as we do not engage in any tracking.

12. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated "Last updated" date. Your continued use of the app after changes are posted constitutes your acceptance of the updated Privacy Policy.

13. Contact Us

If you have questions, concerns, or requests regarding this Privacy Policy or your data, please contact us.