Privacy Policy for AI Journal: Private Diary

Last updated: April 28, 2026

Thank you for using AI Journal: Private Diary ("the App"). Your privacy is our top priority — your journal is the most personal content on your phone. This Privacy Policy explains how we handle your information.

1. Our Core Principle

AI Journal is designed with a privacy-first approach. Your journal content (entries, photos, mood records, AI-generated reflections) is stored exclusively on your device and is never uploaded to our servers. The only data we receive is anonymous, aggregated app-usage analytics and crash diagnostics processed by Google Firebase, which never include the content of your journal.

2. Information Collection

2.1 Locally Stored Data

The following data is stored only on your device and is never uploaded to any server:

• Journal entries (text content, mood, date)
• Activity tags and mood records
• AI-generated analysis results (emotion analysis, reflections, polished text)
• Photos attached to journal entries (stored in App's private directory)
• App preferences (theme, notification settings, lock settings)
• PIN hash (stored locally; we never store your actual PIN)
• AI chat conversation history (stored locally in the App's database)
• Custom writing templates and prompt order preferences

2.2 Anonymous Analytics & Crash Diagnostics

To keep the App stable and improve user experience, we use Google Firebase Analytics and Firebase Crashlytics. These tools collect only the following non-personal, aggregated information:

• App open events, screen views, session duration, retention
• Approximate region/country (derived from IP, IP itself is not retained long-term)
• Device model, OS version, app version, language
• A randomly generated, resettable Firebase Installation ID (not your Google account, not the Android Advertising ID)
• Crash stack traces, ANR reports and the device state at the moment of a crash, to help us diagnose and fix bugs

What is NEVER sent to Firebase or any other server: the text of your journal entries, photos, mood records, AI-generated reflections, AI chat history, your PIN, biometric data, or precise location.

2.3 Information We Do NOT Collect

The App does NOT collect:

• Personal identifying information (name, email, phone number, age, etc.)
• Precise location data
• The Android Advertising ID
• The content of your journal, photos, AI conversations, or mood records
• Contacts, call logs, SMS, or any other device data
• Any information beyond what is described in section 2.2

3. On-Device AI Processing

The App uses AI features (emotion analysis, journaling prompts, text polishing) powered by Google's Gemma 4 model running entirely on your device:

• No cloud processing: Your journal content is never sent to any server, cloud service, or external API for AI analysis
• No AI training: Your data is never used to train or improve AI models
• On-device only: The AI model runs locally on your phone's processor via Android AICore or LiteRT-LM
• Not therapy: AI-generated reflections and emotion analysis are for personal reference only and do not constitute mental health advice

4. How We Use Information

All data stored by the App is used exclusively to provide its core features: journaling, mood tracking, AI reflection, emotion analysis, and statistics. Data never leaves your device.

5. Information Sharing

We do NOT sell your data, and we do NOT share your journal content with anyone. The App contains:

• No advertising SDKs
• No social media SDKs
• No data brokers or marketing trackers

The only data we share is the anonymous analytics and crash diagnostics described in section 2.2, which are processed by Google as our service provider under Google's privacy policy.

6. Third-Party Services

• Firebase Analytics & Crashlytics: Provided by Google. Used to collect anonymous usage statistics and crash reports as described in section 2.2. Journal content is never sent. Uninstalling the App stops all collection immediately. Firebase Privacy & Security
• Google Play Billing: Used only if you choose to subscribe to Pro. Google processes the payment; we receive only a confirmation of subscription status. Pro includes a 3-day free trial; you will not be charged during the trial period. Google's Privacy Policy
• Android AICore / LiteRT-LM: Used for on-device AI processing only. The AI model (Gemma 4 E2B) runs locally on your device — no journal data is sent to Google's servers. LiteRT-LM Documentation
• Google Drive (Optional): If you choose to enable backup, journal data is encrypted and stored in your personal Google Drive appDataFolder. We do not have access to your Google Drive. Data is only uploaded when you explicitly initiate a backup.
• Open-Meteo Weather API: If you enable weather display, the App sends your approximate GPS coordinates to Open-Meteo (a free, open-source weather API) to retrieve current weather. Only coordinates are sent — no personal or journal data. This feature is optional and can be disabled in Settings.

7. Data Security

We take measures to protect your private journal data:

• Local-only storage: All data is stored in the App's private internal storage, inaccessible to other apps
• PIN protection: Optional PIN lock with SHA-256 hashing
• Biometric lock: Optional fingerprint/face unlock via Android BiometricPrompt
• Minimal network access: The App uses INTERNET permission only for optional features (weather display, Google Drive backup, AI model download). Core journaling works fully offline

8. Data Export & Deletion

• Export: You can export all your journal data as CSV or text files at any time from Settings
• Deletion: Uninstalling the App permanently deletes all data stored on your device. We have no backup of your data

9. Children's Privacy

The App does not knowingly collect data from children under 13. As the App collects no data whatsoever, it is inherently compliant with COPPA and similar regulations.

10. Changes to This Policy

We may update this Privacy Policy from time to time. The updated policy will be posted on this page with a revised "Last updated" date.

11. Contact Us

If you have any questions about this Privacy Policy, please contact us at [email protected].