Privacy Policy

Last updated: June 2026

1. Data Collection

Japan Alerts collects the following data to provide its services:

• Anonymous device identifier for push notifications.
• Home location (latitude/longitude) if you choose to set one, to filter relevant alerts and calculate earthquake arrival estimates.
• Language preference and alert preferences (notification settings, shindo threshold, watch zones).
• Group Safety data: if you join a group, your name, safe check-in status, and location during active emergencies are shared with other group members only.
• Diagnostic data: if the app crashes or misbehaves, we collect a crash, error and performance report (device and OS model, app version, a session identifier, and your anonymous device identifier) via Sentry to fix problems and improve stability. We do not attach screenshots of your screen.

2. Data Storage

Your data is stored on Supabase (cloud infrastructure hosted in the EU). Alert data is sourced from JMA (Japan Meteorological Agency) public feeds. All data is transmitted over encrypted connections (HTTPS/TLS).

3. Location Data

Your home location is stored server-side solely to send geographically relevant notifications. During active emergencies, if you have enabled location sharing in a group, your real-time location is shared with group members only. Location data is never shared with third parties or used for advertising purposes. You can change your home location at any time, and have it deleted with the rest of your data via the contact form (see Data Deletion).

4. Push Notifications

We use Firebase Cloud Messaging (FCM) to deliver alerts. Your FCM token is stored solely to send notifications. You can disable notifications at any time from your device settings.

5. Personalization & Conversion Analytics

To make the app more relevant, we personalize some of what you see, for example, the wording on certain screens, based only on the places and preferences you choose to configure (such as the type of a place you save, home, a loved one's, work, a trip, the family or trips you add, and your app language). This personalization is computed on your device. We do not track your movements, browsing, or location history to build a profile, and you can turn it off at any time in Settings > "Personalize what I see"; with it off, you see the app's standard, non-personalized content.

When you purchase a subscription, we record a single snapshot at that moment, the broad profile the personalization had inferred (or "standard" if you turned personalization off), the configured preferences that informed it, the product purchased, and your anonymous device identifier, so we can understand which kinds of users find premium worthwhile. If you have turned personalization off, the snapshot records only "standard," with no inferred preferences. This data is stored on our infrastructure (see Data Storage), is never sold or used for advertising, and is not linked to your name or contact details.

Legal basis: our legitimate interest in operating and improving the app, balanced against your privacy through on-device processing, data minimisation, and the opt-out above (EU/EEA: GDPR Art. 6(1)(f); Japan: APPI).

6. Advertising

The free version displays ads via Google AdMob. We use non-personalized ads only, no user tracking or behavioral profiling. On iOS, we request App Tracking Transparency (ATT) consent before any ad-related data collection. In the EU/EEA, we also request consent via the Google User Messaging Platform (UMP) in compliance with GDPR. Premium subscribers see no ads.

7. Third-Party Services

The app uses the following third-party services, each with their own privacy policy:

• Google AdMob (advertising), google.com/policies/privacy
• RevenueCat (subscription management), revenuecat.com/privacy
• Firebase Cloud Messaging (push notifications), firebase.google.com/support/privacy
• Supabase (data storage), supabase.com/privacy
• Sentry (crash and performance diagnostics), sentry.io/privacy

8. Data Retention

Alert data is retained for statistical purposes (up to 365 days). User profiles and preferences are retained as long as your account exists. Group data is deleted when you leave or delete a group. Conversion snapshots are pseudonymous (linked only to your anonymous device identifier, never your name) and are retained for the analysis described above, then deleted or anonymised; you may request earlier deletion (see Data Deletion).

9. Data Deletion

From Settings > Offline Data, "Clear offline data" removes the shelters saved on your device for offline use. To delete your server-side data, your profile, preferences, group data, and conversion record, contact us through the app and we will erase it.

10. Children

This app is not directed at children under 13. We do not knowingly collect personal data from children.

11. Changes to This Policy

We may update this policy from time to time. The updated version will be indicated by the "Last updated" date. Continued use of the app after changes constitutes acceptance.

12. Contact

For questions about this privacy policy, contact us at contact@artisanlogiciel.com or through the in-app contact form.

This policy applies to the Japan Alerts app, published by Artisan Logiciel (legal notice).