Privacy Policy

Article 1 (App provider information)

Engineer BA-Sulto (“we,” “us”) provides the app “Arujikan” (Japanese Walking Timer) (the “App”). We take the protection of users’ personal information and privacy seriously and set forth this Privacy Policy (“Policy”) as follows.

Article 2 (Types of information and purposes of use)

We collect the following information in the App and use it for the purposes stated.

2.1 Information stored on the device only (no external transmission)

  • Profile (nickname, age, gender, exercise experience): Automatic timer suggestions and optimal walking plan proposals
  • Feedback (type, rating, description, attached images): Stored in the app only; we may review it to improve service quality
  • Training history: Progress display and habit support

The above is stored on the device (SQLite / AsyncStorage) and is not sent to our servers.

2.2 Information transmitted externally

  • Email address: Replies to inquiries and important notices (only if you contact us by email)
  • Usage events (timer start/complete, settings changes, sharing, etc.): Service improvement and usage analytics (Firebase Analytics)
  • Crash reports and error information: Bug investigation and improvement (Firebase Crashlytics)
  • Advertising identifiers (IDFA / AAID): Ad delivery optimization (Google AdMob)
  • Device information (OS type/version, language settings, etc.): App optimization and analytics
  • IP address: Fraud prevention and access analytics
  • Purchase information (anonymous user ID, purchase receipt, transaction information, purchase status): Processing of in-app purchases, management and restoration of purchase status (RevenueCat / App Store / Google Play)

Article 3 (How we collect information)

We collect information by the following means:

  1. Direct input: Information you enter in forms or settings in the App
  2. Automatic collection: Information collected automatically when you use the App via the modules described below
  3. Inquiries: Content of inquiries sent to our email address

Article 4 (External transmission and information collection modules)

[Disclosure based on the Telecommunications Business Act, Article 27-12]

For service improvement and advertising, the App uses the following third-party tools (information collection modules). Information may be sent from your device to the providers’ servers.

  • Firebase Analytics
    • Provider: Google LLC
    • Information sent: Usage events, device information, IP address
    • Purpose: Usage analytics and service improvement
    • Privacy policy: https://policies.google.com/privacy
  • Firebase Crashlytics
  • Google AdMob
    • Provider: Google LLC
    • Information sent: Advertising identifiers (IDFA/AAID), behavioral data
    • Purpose: Ads matched to users’ interests
    • Privacy policy: https://policies.google.com/privacy
  • RevenueCat
    • Provider: RevenueCat, Inc.
    • Information sent: Anonymous user ID, purchase receipts, transaction information, device information
    • Purpose: Processing in-app purchases, management and restoration of purchase status
    • Privacy policy: https://www.revenuecat.com/privacy
  • Apple App Store
    • Provider: Apple Inc.
    • Information sent: Purchase receipts, payment information associated with your Apple ID
    • Purpose: In-app purchase processing (iOS)
    • Privacy policy: https://www.apple.com/legal/privacy/
  • Google Play Billing
    • Provider: Google LLC
    • Information sent: Purchase receipts, payment information associated with your Google account
    • Purpose: In-app purchase processing (Android)
    • Privacy policy: https://policies.google.com/privacy

Tools used may change; we will update this Policy when they do.

Article 5 (Photo library access)

The App may request access to your photo library for:

  • Saving training result images to the library
  • Attaching screenshots when sending feedback

Selected images become part of feedback data stored on the device and are not sent to our servers.

Article 6 (In-app purchase information)

The App includes in-app purchase features such as the Ad-Free plan and Pro plan (subscriptions and one-time purchases).

  1. Payment processing itself is performed by the Apple App Store (iOS) or Google Play Store (Android); we do not obtain or store payment information such as credit card numbers.
  2. To manage and restore purchase status, we use RevenueCat (provided by RevenueCat, Inc.) and send anonymous user ID, purchase receipts, transaction information, and similar data to its servers.
  3. The purchase information we receive is not separately stored on our own servers and is used only to verify purchase status and respond to user inquiries.

Article 7 (Disclosure to third parties)

We do not provide personal information to third parties without your consent, except:

  1. When required by law (e.g., lawful requests from courts or law enforcement)
  2. When necessary to protect life, body, or property and obtaining consent is difficult

Article 8 (Storage and security)

  1. We store personal information we obtain with appropriate security measures.
  2. Access to personal information is limited to what is necessary for our operations.
  3. We use SSL/TLS encryption to ensure safety during transmission and reception of data.
  4. We delete information that is no longer needed for its purpose within a reasonable period, using secure methods.

Article 9 (Disclosure of personal information)

  1. When you request disclosure of your personal information, we will disclose it to you without undue delay.
  2. How to request: Contact us through the inquiry channel below. After identity verification, we will respond without undue delay.

Article 10 (Correction and deletion)

  1. If your personal information we hold is incorrect, you may request correction or deletion.
  2. If we determine that a request should be honored, we will correct or delete the information without undue delay and notify you.
  3. Profile and feedback data stored on the device can be removed by deleting app data or uninstalling the App.

Article 11 (Suspension of use, etc.)

  1. You may request that we stop using or erase your personal data.
  2. Uninstalling the App stops automatic collection of certain information.
  3. You may limit ad identifier tracking in device settings.
  4. To disable Firebase Analytics data collection, uninstall the App.

Article 12 (Children’s privacy)

The App is not directed at children under 9. We do not knowingly collect personal information from children under 9. If we learn that we have collected such information, we will delete it promptly.

Article 13 (Changes to this Policy)

  1. We may change this Policy without notice except where required otherwise by law.
  2. For material changes, we will notify you in advance via in-app or push notifications.
  3. Unless we specify otherwise, the revised Policy takes effect when posted in the App.

Article 14 (Contact)

For questions about this Policy, contact:

  • Provider name: Engineer BA-Sulto
  • Contact: info@engineer-ba-sulto.com
  • Hours: Weekdays 10:00–17:00 (excluding weekends, holidays, and year-end/New Year)
  • Response time: In principle within 14 business days of receipt

Last updated: April 19, 2026