Privacy Policy

StructFlow — DSA Visualizer · Last updated: July 11, 2026

1. Information We Collect

1.1 Account Information Optional

If you choose to create an account or sign in, we collect:

• Email address — for authentication and account recovery
• Display name — shown in your profile
• Profile photo URL — if you sign in with Google

You can use the app as a guest without providing any personal information.

1.2 Learning Progress

We store your learning progress data, including:

• Topics completed and quiz scores
• Experience points (XP) and level
• Study streaks and achievements
• Bookmarks and notes

This data is stored locally on your device and, if you sign in, synced to Google Cloud Firestore so you can access it across devices.

1.3 Automatically Collected Data

• Firebase Analytics — anonymous usage statistics (screens viewed, feature usage) to improve the app experience. No personally identifiable information is collected.
• Device information — device model, OS version, and app version for crash reporting and compatibility.

2. Advertising

3. How We Use Your Information

• To provide and maintain the learning experience
• To sync your progress across devices (if signed in)
• To display relevant advertisements (free users on Android)
• To improve app functionality and fix bugs
• To send study reminders (if enabled by you)

4. Data Storage & Security

• Local storage — Learning progress is stored on your device using a local database and SharedPreferences.
• Cloud storage — If signed in, data is synced to Google Cloud Firestore, protected by Firebase Security Rules.
• Authentication — Handled by Firebase Authentication with industry-standard encryption.

5. Third-Party Services

We use the following third-party services:

• Firebase (Authentication, Firestore, Analytics) — by Google
• Google AdMob — advertising (Android app, free users only)

6. Data Sharing

We do not sell, trade, or share your personal information with third parties, except as described in this policy (Firebase for sync, AdMob for ads).

7. Children's Privacy

StructFlow is an educational app suitable for users aged 13 and above. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided personal information, please contact us so we can delete it.

8. Your Rights

• Access — View your data within the app (Profile section)
• Delete — Delete your account and all associated data from Settings
• Guest mode — Use the app without creating an account
• Ad preferences — Opt out of personalized ads via your device settings

9. Changes to This Policy

We may update this privacy policy from time to time. Changes will be posted on this page with an updated revision date.

10. Contact Us