Privacy Policy

Last updated: November 13, 2025

This Privacy Policy describes how the application “Henkankun” (the “App”) handles information and how that information is used. We prioritize protecting user privacy and handle information in accordance with this policy.

1. Scope of Application

This policy applies to all users of the App and any third-party services integrated into the App. It does not apply to third-party websites or apps linked from the App.

2. Information We Collect

The App does not require user registration or the input of personally identifiable information. To provide its features, the App stores the following information on the device:

• Conversion history and calculation results (for display and reuse in the history screen)
• Conversion pairs saved as favorites
• Search history and data needed to display search suggestions
• App settings (language, theme, rounding rules, default categories, and similar preferences)
• In-app counters such as whether ads are shown and how many times the App has been opened

These data are stored unencrypted in the device’s local database (Hive) and shared preferences area (SharedPreferences). They are not sent to our servers or other parties, except as described under Third-Party Services below.

3. Purposes of Use

• To provide and improve core App features such as unit conversion and history display
• To preserve display settings and customization based on user actions
• To analyze causes of issues and prevent fraudulent or abusive use
• To control ad delivery conditions and remote configuration values

4. Information Provided to Third Parties

The App uses the following third-party services. Information sent to each service is managed under that service’s privacy policy.

4-1. Google Mobile Ads (AdMob)

The App uses the Google Mobile Ads SDK to deliver App Open Ads shown at startup. For ad delivery, Google may collect the advertising ID, IP address, operating system and device information, and App usage data. For details, see the Google Privacy Policy.

4-2. Firebase Remote Config

To flexibly update ad unit IDs and delivery rules, the App retrieves configuration values using Firebase Remote Config. When doing so, the App version, OS information, language settings, and an anonymous device identifier may be sent to Google. Retrieved values are used only within the App and not to identify users. For more on Firebase data handling, see Firebase Privacy and Security Information.

5. Data Retention and Deletion

Data stored on the device are retained until the user deletes them. You can delete history or favorites from the corresponding screens. To remove all settings and data, delete the App’s data from the device settings or uninstall the App. Data will not be restored even if the App is reinstalled.

6. Use by Minors

The App has no age restrictions, but users under 13 must obtain consent from a parent or guardian. We do not knowingly collect personal information from minors.

7. Changes to This Policy

We may revise this policy as needed. For significant changes, we will provide notice within the App or on an official site before applying the updates. Continued use of the App after changes take effect constitutes acceptance of the updated policy.

8. Contact

For questions about this policy, please contact us via the developer contact listed in each app store or through the store’s review function.

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