Privacy Policy

The Japanese version is the original and authoritative text. This English version is provided as a reference translation. If there is any conflict, the Japanese version prevails to the extent permitted by law.

1. Operator and scope

OTS-International CO.,LTD. (“we,” “us,” or “our”) handles information in the mobile application “Just a Calculator - That Works” (shown on the device as “Just a Calculator”; Japanese name: “或る電卓”), its website, and related online features (the “Service”) under this Policy.

2. Information we handle

Information stored only on your device

Standard calculator history, display-digit, rounding, tax-rate, sound, and vibration settings, and history for on-device Olympic scoring are generally stored only on your device and are not sent to our server.

Account and event information

If you use online events or account features, we handle account identifiers, authentication and session information, protected values used for recovery, a matching hash for a verified email address, display names, event names and dates, participant names, scores, participation status, and invitation or access information. We do not store recovery codes or passwords in plain text.

Purchase information

The one-time Ad-Free purchase (app version 1.2.0 and later) can be bought and restored without an account. Its status is checked only between your device and Apple (App Store) or Google (Google Play); purchase tokens and transaction information are not sent to our server. Apart from the sales and order records we receive from the stores, we keep nothing that links this purchase to you.

If you buy or restore the monthly feature (Event Plus), or bought Ad-Free through an account in a version before 1.2.0, we handle the product ID, store, transaction or order identifiers, purchase tokens or signed transaction information, entitlement status, expiration, and verification results on our server to apply the benefit to your online account.

In either case, Apple or Google processes your card or other payment method; we do not receive card numbers.

Ads, consent, and technical information

In the free version, the Google Mobile Ads SDK and related services may handle advertising identifiers, IP address, device, OS and app information, approximate location, ad impressions and interactions, diagnostic information such as crash and performance data, and consent status. We may also handle limited technical logs such as request time, response status, and device or network information for security and troubleshooting.

Support information

We handle the name, email address, message, attachments, and correspondence that you submit through Google Forms or email. Whether the form collects Google Account information depends on the settings and notices shown in the form.

Camera and sharing

The camera is used to scan event invitation QR codes. It is not used to save the scanned image itself to our server. A calculation or results image is sent to a destination only when you choose the device’s sharing function and select that destination.

3. Purposes

Provide calculations, history, settings, and event creation, participation, scoring, and sharing
Verify identity, protect and recover accounts, and support multiple devices
For purchases tied to an account, such as the monthly feature, verify them, unlock and restore features, and process refunds or revocations
Deliver ads and apply your consent choices
Respond to support requests, diagnose faults, and improve quality and security
Enforce our Terms, prevent abuse, and comply with law

4. Service providers and disclosure

We may entrust or transmit information to the following providers as needed for the stated purposes:

Google LLC: Google Play distribution, billing and purchase verification; AdMob advertising and consent management; Google Forms
Apple Inc.: App Store distribution, billing, and purchase verification
Cloudflare, Inc.: API, database, security, and delivery infrastructure
Email delivery provider: verification codes and account-related notices

We do not disclose personal data to third parties for unrelated purposes unless required by law, necessary to protect life or property, part of a business transfer, or authorized by you.

5. Advertising and your choices

We use Google AdMob and the User Messaging Platform for advertising and consent management. Depending on region, consent, and device privacy permissions, the app may show personalized or non-personalized ads. You may be able to revise your choice through the consent screen or device advertising settings. On iOS, the app asks for your permission through App Tracking Transparency (ATT), and only if you allow it may your advertising identifier be used to show and measure ads across other companies’ apps and websites. You can change this at any time in Settings > Privacy & Security > Tracking, and declining does not limit any app feature or purchase. On Android, you may be able to reset or delete your advertising ID in device settings. See the Google Privacy Policy for Google’s practices.

6. International processing

Information may be processed outside Japan because the providers above operate facilities or offices in other countries. We take steps required by applicable law, including reviewing appropriate safeguards of service providers.

7. Retention and deletion

On-device history and settings may remain until you remove them in the app, clear app data, or uninstall the app. Online account and event information is retained as needed to provide features, perform contracts, maintain security, verify purchases, comply with law, and resolve disputes, then deleted or anonymized.

After account deletion, we keep sales records for accounting and tax purposes for 7 years and technical logs for fraud prevention and security for up to 1 year; information in backups is erased as the backups are rotated. See Delete your account for the steps and what is deleted.

8. Security

We use reasonable safeguards appropriate to the information, including encrypted transport, protection of access tokens, encryption of purchase information, access controls, and monitoring. No internet transmission or storage can be guaranteed completely secure.

9. Your rights and choices

Subject to applicable law, you may request access, correction, restriction, or deletion of your personal information. You can request account deletion in the app. Ad choices may be revised through the consent screen or device settings. We may ask you to verify your identity before completing a request.

10. Children

The Service is not designed for children who cannot provide personal information without parental consent. Such users should use the Service with a parent’s consent and supervision. If we learn that a child’s information was provided improperly, we will take steps such as deletion.

11. Changes

We may update this Policy for functional, legal, or operational changes. We will announce material changes on this page or in the app and show the updated date.