Official Legal Document

Privacy Policy

Application: RevLog (Spaced-Repetition Revision & Question Bank) Effective Date: September 16, 2026 Last Updated: September 16, 2026

1. Overview & Core Philosophy

RevLog ("we", "our", or "the app") is an offline-first, intelligent spaced-repetition revision companion and question bank application designed to help students prepare for competitive entrance examinations (including NEET, JEE Main, and JEE Advanced).

Our core engineering principle is complete data ownership and local privacy. RevLog operates locally on your mobile device. We do not run external tracking servers, we do not require account registration on proprietary third-party backends, and we do not monetize or harvest your study materials.

2. Google Drive API & Application Data Usage

RevLog provides an optional Cloud Backup & Sync feature that allows users to safeguard their revision database and study images across devices using their own personal Google Drive account.

Strictly Scoped Google Drive Access (Least Privilege)

RevLog requests exactly one Google OAuth scope:
https://www.googleapis.com/auth/drive.appdata

This scope grants access strictly and exclusively to Google Drive's isolated Application Data folder (appDataFolder). It is a private, hidden folder dedicated solely to RevLog.

What RevLog Can and Cannot Access

To ensure total transparency, here is a breakdown of RevLog's permissions on Google Drive:

Data Category Can RevLog Access? Details
RevLog Backup Files (revlog_database.db, question images) YES (Read & Write) Only files created by RevLog inside the private appDataFolder.
Personal Google Drive Documents & Files (Docs, Sheets, Slides, PDFs) NO (Zero Access) RevLog cannot view, read, search, list, or modify any user personal files.
Google Photos & Media NO (Zero Access) RevLog has no permission to interact with Google Photos or personal media libraries.
Drive Directory Structure / Shared Drives NO (Zero Access) The Application Data folder is invisible to standard Drive views and isolated from user directories.

Exact Google Drive Data Operations Performed

  • Database Backup: Periodically checkpoints the local SQLite database into a snapshot file named revlog_database.db and transfers it via encrypted HTTPS to the user's private appDataFolder.
  • Question & Solution Images: Uploads captured study diagrams, solutions, and question images directly into appDataFolder and maintains a synchronizing index (manifest.json).
  • Cloud Restore: Allows the user to restore their complete question bank and spaced repetition intervals onto a new device by reading directly from their appDataFolder.

3. Google API Services User Data Policy (Limited Use)

Mandatory Google API Compliance Statement

RevLog's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

In adherence to Google's Limited Use requirements:

  • We do not transfer data received from Google Drive to any third party, other than directly between your device and Google's official Drive endpoints.
  • We do not use or transfer data from Google APIs for serving advertisements, retargeting, or personalized profiling.
  • We do not use data obtained from Google APIs to train generalized artificial intelligence (AI) or machine learning (ML) models.
  • Human humans/employees are not permitted to view your stored Google Drive data under any circumstances.

4. Data We Process & Collect

RevLog collects and processes the minimum information necessary to deliver offline-first spaced repetition:

👤 Google Profile Data

When you choose to sign in with Google, we temporarily receive your name, email address, and avatar URL. This information is saved locally in encrypted device storage (Expo SecureStore) solely to show your signed-in state in the Settings tab.

📚 Question Bank & Study Data

Questions, MCQ/MSQ/NAT answer keys, topic taxonomies (Physics, Chemistry, Math, Biology), handwritten or printed notes, and attempt history are saved locally in an on-device SQLite database.

⏱️ Spaced Repetition (SRS) Metrics

Stage intervals (1 → 3 → 7 → 15 → 30 → 60 → 120 → 240 → 365 days), next revision due dates, accuracy scores, and session timestamps used by the on-device scheduling engine.

🖼️ Question & Solution Images

Photographs captured via camera or selected from device gallery are downscaled to 720p and saved directly to the sandboxed application directory on your physical device.

5. Device Hardware Permissions

RevLog requests native system permissions only when you explicitly trigger related features:

  • Camera (android.permission.CAMERA): Used solely to capture photographs of question papers, textbook problems, and hand-written solution steps. Photos are processed locally.
  • Media Library / Gallery: Used only when you select an existing diagram or question screenshot from your device gallery.
  • Microphone (Optional): Used only if you record personal audio notes attached to a question card. Audio is kept locally.
  • Notifications: Used only to trigger local alerts reminding you of daily revision sessions scheduled by the spaced repetition algorithm.

6. Data Sharing, Selling & Monetization

RevLog adheres to an uncompromising no-monetization-of-data policy:

  • Zero Sale of Data: We have never sold, rented, leased, or monetized user information or study material, and we will never do so in the future.
  • No Ad Networks: RevLog contains zero advertising SDKs (no Google AdMob, Facebook Audience Network, or tracking pixels).
  • No Third-Party Analytics Trackers: We do not embed behavioral tracking tools that monitor your activity across apps.
  • Direct P2P Cloud Sync: When backing up or restoring, your device talks directly and exclusively to Google's official endpoints over TLS/HTTPS. RevLog does not route your traffic through an intermediary proxy.

7. Data Storage & Security Safeguards

We implement industry-standard safeguards to protect your study materials:

  • Isolated Sandboxing: All local SQLite database tables, migration states, and question images reside inside the operating system's private app sandbox, preventing other installed apps from accessing them.
  • Secure Token Storage: Google OAuth tokens and credentials are encrypted on-device utilizing Android KeyStore / iOS Keychain via expo-secure-store.
  • Integrity Checks: Restored database snapshots are verified with magic byte headers (SQLite format 3\0) to prevent corrupted or malicious database ingestion.
  • Transport Security: All communications with Google Drive APIs are encrypted end-to-end using modern TLS 1.3 / HTTPS.

8. Data Retention & User Deletion Rights

You have full autonomy over your data and can delete it at any time:

How to Delete Your Data

1. Delete In-App: You can delete any individual question or your entire question bank from within RevLog. Deleting a question purges the SQLite database entry and immediately deletes the local image file.

2. Delete Google Drive Backups: To remove all cloud backup data stored in your Google Account:

  1. Open Google Drive on your desktop browser.
  2. Click the Gear Icon (Settings) → Settings → Manage Apps.
  3. Locate RevLog in the list.
  4. Click Options → Delete hidden app data.

3. Revoke Google Access: You can disconnect RevLog from your Google Account at any time by visiting Google Account Permissions and revoking access for RevLog.

9. Children's Privacy

RevLog is designed for students preparing for higher secondary and competitive examinations (such as NEET, JEE, and college entrance tests). We do not knowingly collect personal identifiable information from children under the age of 13. If you believe an underage child has provided personal information without parental consent, please contact us immediately so we can remove it.

10. Contact & Developer Information

If you have questions, feedback, or data privacy inquiries regarding this Privacy Policy or RevLog's Google Drive integration, please reach out directly: