Last updated: 2026-03-28

Privacy Policy

Last updated: March 28, 2026

Overview

MiDiccio is a local, personal vocabulary learning app. This policy explains how the app collects, uses, and protects personal data.

1. Data Collection

1.1 Data Stored (User-provided and Automatically Recorded)

Following the principle of minimal data collection, only the following data is stored:

1.2 Data We Do Not Collect

We do not collect any of the following:

• ❌ Personally identifiable information such as name, address, or phone number
• ❌ User profile or authentication credentials (no local account/auth)
• ❌ Location information
• ❌ Device IDs (including analytics use)
• ❌ Learning behavior analytics (access frequency, study time, etc.)
• ❌ Cookies or tracking data

2. Data Storage

2.1 Local Storage (On Device)

All learning data is stored in secure local storage on your device.

• Technical method: Hive local persistence
• Location: iOS/Android app sandbox
• Owner: User (removed automatically when the app is uninstalled)

2.2 Cloud Sync

In the current version, cloud sync runs at the following timing:

Important:
- When a cloud sync client is enabled, the app issues auto-sync requests on app resume, after save, and after delete
- Users can also run manual sync from settings using Sync Now
- Network transfer occurs only when a sync execution runs (to iCloud on iOS, Google Drive on Android)

2.3 Data Transfer Security

: Locally stored data is protected at the OS level via sandboxing, device encryption, and lock-screen protections.
: In the current version, cloud transfer occurs only when sync executes, either by manual sync or lightweight auto-sync triggers.

3. Data Sharing

3.1 Sharing with Third Parties

We do not share personal data with third parties.

Cloud sync transfers data only to the user's own iCloud or Google Drive. The developer has no access to any user data.

3.2 Cloud Provider Privacy Policies

When cloud sync is used, the following privacy policies also apply:

• Google Drive (Android): Google Privacy Policy
• iCloud (iOS): Apple Privacy Policy

MiDiccio integrates these services as a licensee and does not perform secondary data usage.

4. User Rights

4.1 Right to Access Data

Users can access data by:

1. In-app: View data in learning screens
2. Backup file: Complete export available in JSON format
3. Android cloud sync: Check sync status and logs in settings
4. iOS cloud sync: Check sync status and logs in settings

4.2 Right to Delete Data (Right to be Forgotten)

Users can delete data by:

4.3 Right to Data Portability

Users can export data anytime:

[Menu] → [Backup/Restore] → [Save Backup]

Export files are JSON and can be processed by other tools.

5. Security Measures

5.1 Currently Implemented

• ✅ Local storage: Hive with native sandboxing
• ✅ Input validation: Required UI form validation + Hive type consistency
• ✅ Network communication: SSL/TLS during iOS iCloud sync and Android Google Drive sync
• ✅ Access control: Accessible only by the device owner
• ✅ Offline-first: No server dependency

5.2 Encryption

The app does not implement its own application-level encryption. Data protection relies on the mechanisms provided by the OS and platform:

• Local data: OS sandbox, device encryption, and screen lock (iOS/Android OS)
• Data in transit: SSL/TLS (Apple CloudKit / Google Drive API)

5.3 Security Reporting

If you find a security vulnerability, please report it through a private channel instead of a public issue:

- Use “Report a vulnerability” from the repository Security tab (Private vulnerability reporting)
- See SECURITY.md for details

6. Compliance

6.1 Applicable Privacy Regulations

This app aligns with:

1: Local-only storage and no third-party sharing minimize personal information handling.
2: EU users are protected by the same privacy principles above.

6.2 Regions Covered by This Policy

• Japan
• Other countries/regions (including GDPR-covered regions)

7. Changes to This Privacy Policy

When this policy changes, updates are communicated as follows:

1. Major changes: In GitHub release notes and this document
2. Minor updates: In GitHub release notes

The update date is always reflected in “Last updated”.

8. Contact

If you have questions or concerns regarding privacy or security, please open an issue on GitHub:

GitHub Issues: https://github.com/kazweda/midiccio/issues

9. Policy Version History

This policy will be updated as the app evolves.