Privacy Policy

For a summary organized by each kind of information, see also Handling of Personal Data.

1. Information we collect directly

RYURAKU has no account registration or sign-in. We do not operate servers and do not collect or store information that identifies you, such as your name, email address, phone number or precise location (GPS).

The only things the app saves on your device are your theme setting (light / dark) and your personalized-ads choice (allow / don't allow). They are stored only on the device (shared_preferences) and are never sent anywhere. Simulation parameters are held temporarily on the device and are discarded when the app closes.

2. Information collected by a third-party service (ads)

The app includes the SDK of Pangle, an advertising service provided by Bytedance Pte. Ltd., and shows a banner ad at the bottom of the screen. For ad delivery and display, measurement, frequency capping and fraud prevention, the Pangle SDK may send the following information directly to Pangle:

• Advertising identifier (IDFA on iOS only if you allow tracking / advertising ID on Android)
• IP address and the approximate region inferred from it
• Device information (model, OS, language, screen size, etc.)
• Ad interactions such as impressions and clicks, and SDK diagnostic information

This information is sent directly to Pangle by the SDK embedded in the app; we do not receive or sell it. For how Pangle handles information, see the Pangle Privacy Policy.

3. App Tracking Transparency (iOS only)

On iOS, following Apple's privacy requirements, the app shows the tracking permission dialog after launch. The ad SDK (Pangle) does not start until you respond. Personalized ads are shown only if you allow tracking and also allow them in the app's "Ad settings" (allowed by default). If you choose "Ask App Not to Track", the IDFA is not used and non-personalized ads are shown. All features of the app remain available. You can change this at any time in iOS Settings > Privacy & Security > Tracking.

You can also turn off personalized ads even when tracking is allowed by choosing "Don't allow" in "About this app" > "Ad settings" (non-personalized ads will still be shown).

4. Personalized-ads choice and advertising ID (Android)

On Android, the app asks at first launch whether ads may be personalized ("Allow" / "Don't allow"). The ad SDK (Pangle) does not start, and nothing is sent to Pangle, until you answer. If you choose "Don't allow", ads are still shown but are not personalized. You can change your choice at any time from "About this app" > "Ad settings". The choice is stored only on your device and is excluded from Android backup and device-to-device transfer, so a new device will ask again.

On Android you can also reset or delete your advertising ID from Settings > Privacy > Ads (on some devices Settings > Google > Ads; this varies by device and OS version).

5. Sharing or selling data

Apart from the ad delivery described above (Pangle), the app does not share or sell your information to third parties. The app has no in-app purchases or subscriptions.

6. Deleting data

We do not store your information on any server, so we hold no data to delete. The theme setting and personalized-ads choice on your device are removed when you uninstall the app. For information collected by Pangle, please contact Pangle through the Pangle Privacy Policy above.

7. Children

The app is intended for students and the general public and is not directed at children under 13. We do not knowingly collect information from children under 13.

8. Changes to this policy

This policy may change as laws or the service change. Any changes will be posted on this page.

9. Contact

For questions about this policy, please contact support@fujibit.com.