Privacy Policy

1. Information We Collect

When you use OMR Grader, we collect the following types of information:

• Account Information: Your email address, name, and authentication method (email/password or Google Sign-In) when you create an account.
• Scan Data: We record scan counts and types (camera, gallery, batch) for enforcing daily limits and internal analytics. Answer sheet images are processed entirely on your device and are never uploaded to our servers.
• Subscription Information: Purchase tokens and subscription status from Google Play Billing for managing premium features.
• Device Information: Device model, Android version, and app version for troubleshooting and compatibility improvements.
• Usage Analytics: We use Firebase Analytics to collect anonymous usage data such as feature usage, screen views, and engagement metrics. This data does not personally identify you.
• Crash Reports: Firebase Crashlytics collects technical crash data (stack traces, device state) to help us fix bugs and improve app stability.

2. How We Use Your Information

We use the information we collect to:

• Provide, maintain, and improve the OMR Grader service
• Manage your account, authentication, and subscription status
• Enforce daily scan limits for free-tier users
• Improve app performance and fix bugs via crash analytics
• Understand feature usage to prioritize development
• Communicate important service updates

3. Image Processing — On-Device Only

OMR Grader processes answer sheet images entirely on your device using local image processing algorithms. Your scanned images are never transmitted to or stored on our servers.

Processed result data (scores, answers, grade breakdowns) is stored locally on your device in the app's private database. Only aggregate scan counts are synced to the server for limit enforcement.

4. Data Storage & Security

Your account data is transmitted over encrypted connections (HTTPS/TLS). Passwords are securely hashed on the server — we never store plaintext passwords.

Authentication tokens are stored locally on your device using Android's EncryptedSharedPreferences (AES-256 encryption). Session tokens expire after 1 hour and refresh tokens after 30 days for added security.

5. Third-Party Services

OMR Grader uses the following third-party services, each governed by their own privacy policies:

• Google Firebase (Analytics & Crashlytics) — Anonymous usage analytics and crash reporting. See Google's Privacy Policy.
• Google Play Billing — Processing premium subscription purchases. Subject to Google Play's Terms of Service.
• Google Sign-In — Optional authentication via your Google account. Subject to Google's Privacy Policy.

6. Data Retention

We retain your account data for as long as your account is active. If you choose to delete your account, your personal data is anonymized within our system — your email is replaced and your name is cleared. Anonymous scan statistics may be retained for aggregate analytics only.

Local data (scanned images, exam results, answer keys, sheet templates) is stored only on your device and is permanently removed when you uninstall the app or clear app data.

7. Your Rights

You have the right to:

• Access your personal data through your in-app profile screen
• Update your name and account information at any time
• Delete your account and all associated data — see our Account Deletion page
• Opt out of analytics by disabling Firebase Analytics in your device settings

For users in the European Economic Area (EEA), you additionally have the right to data portability and to lodge a complaint with your local data protection authority (DPA).

For users in California (CCPA), you have the right to know what data we collect, request its deletion, and opt out of its sale (we do not sell your data).

8. Children's Privacy

OMR Grader is designed for educators and is not directed at children under 13 years of age. We do not knowingly collect personal information from children under 13. If we learn that we have inadvertently collected personal information from a child under 13, we will delete that information promptly. If you are a parent or guardian and believe your child has provided us with personal data, please contact us at the email below.

9. International Data Transfers

Your information may be processed on servers located outside your country of residence. We ensure that any transfers comply with applicable data protection laws and that appropriate safeguards are in place to protect your data.

10. Changes to This Policy

We may update this privacy policy from time to time. We will notify you of any material changes by posting the updated policy in the app and on this page, and updating the "Last updated" date at the top. Continued use of the app after changes constitutes acceptance of the updated policy.

11. Contact Us

If you have any questions about this privacy policy, your data, or wish to exercise any of your rights, please contact us at:

You can also reach us through our in-app support channel for feedback and suggestions.