arc habit
Privacy Policy
Last updated: September 1, 2026
This Privacy Policy explains how arc habit (the "App") handles user information.
Information We Collect
We may collect the following information to provide, improve, secure, and operate the App.
- Account information: user identifiers managed by Firebase Authentication and authentication-related information.
- Usage data: habits, activity logs, settings, and other information entered or recorded in the App.
- Device and usage information: app usage, crash data, performance data, device information, and advertising identifiers.
- Purchase information: in-app purchase status, subscription status, and transaction-related information.
Purposes of Use
- To provide the App, authenticate users, sync data, and save settings.
- To analyze usage, improve features, and enhance quality.
- To investigate crashes, respond to incidents, and maintain security.
- To display ads, measure ad performance, and prevent ad fraud.
- To verify in-app purchases, subscriptions, and purchase status.
- To respond to legal or policy requirements.
Third-Party Services
The App may use the following third-party services.
- Firebase Authentication
- Cloud Firestore
- Firebase Analytics
- Firebase Crashlytics
- Firebase Cloud Messaging
- Firebase Remote Config
- Firebase Performance Monitoring
- Google AdMob
- Apple App Store / Google Play in-app purchase services
Please refer to each provider's privacy policy for details about information collected by those services.
Ads and Tracking
The App may display ads through Google AdMob. Advertising identifiers, device information, and ad interaction data may be used for ad delivery. On iOS, the App will request permission under App Tracking Transparency when required.
Connecting External AI Services (Optional)
The App includes an optional feature that lets an external AI service (such as Claude) read your habit records. This feature is off by default. It becomes active only when you generate a connection code in the App's settings and enter it in the AI service. No information is sent through this feature while no connection exists.
Once connected, the following information is sent in response to requests from the AI service:
- The name, amount, and date/time of your recorded habits.
- Aggregates of the above, such as the number of days or times you recorded.
The following information is not sent:
- Profile information such as your display name.
- Information about who you follow or who follows you.
- Your notification settings.
The connection is read-only; the AI service cannot modify or delete your records. You can disconnect at any time from the App's settings, which stops any further reading.
Transfers to Third Parties Outside Japan
The provider of an AI service you choose to connect may be located outside Japan. The provider of Claude, which the App presents as a connection target, is Anthropic PBC, located in the United States. By completing the connection, you consent to the provision of the information described above to that provider.
For details on how the recipient handles personal information, the data protection framework of the recipient's country, and the safeguards the recipient applies, please refer to that provider's privacy policy. If you connect an AI service other than the one presented by the App, the recipient and its location are of your own choosing.
Disclosure to Third Parties
We do not provide personal information to third parties without user consent, except as required by law. Information may be sent to third-party providers as necessary to use the services listed above. In addition, information is sent within the scope described in "Connecting External AI Services" only if you enable that feature yourself.
Security
We take reasonable measures to prevent leakage, loss, or damage of collected information.
User Choices
Users may be able to change notification, advertising identifier, and tracking settings through device or in-app settings. For inquiries about account information or saved data, please contact us.
Changes
We may update this Privacy Policy as necessary. Important changes will be announced on this page or in the App.