Privacy Policy

Effective and last updated: July 20, 2026

Hikaru Yamaguchi (the “Operator”) establishes this Privacy Policy for the handling of information in the technical article management application Tsumitec (the “App”).

1. Information handled by the App

The following information is handled in connection with your use of the App's features:

• Saved article URLs, titles, site names, OGP descriptions, image URLs, and favicons
• Article tags, notes, read status, and related timestamps
• URLs, tags, and notes received through the Share Extension or Android sharing
• Usage information such as screen views, article actions, tag actions, and searches
• Crash data, stack traces, and device, OS, and app information
• Device information, identifiers, IP addresses, and related data used for ads and consent
• Feedback type, details, and reproduction steps that you voluntarily enter and submit to Google Forms opened in an external browser

The App has no user account or cloud sync feature. It does not include search terms, article URLs, titles, or notes in Firebase Analytics events.

2. On-device storage

Articles, tags, notes, read status, and related information are generally stored in a SQLite database on your device. On iOS, URLs, tags, and notes received by the Share Extension are stored temporarily in an App Group container until they are imported into the App. On Android, shared text is passed directly to the App and is stored in the SQLite database after you complete the save operation.

You can delete articles and tags in the App. You can also delete remaining on-device data by uninstalling the App. The Operator cannot access or remotely delete information stored on your device.

3. Connections to external websites

When you add an article URL, the App connects to that website to retrieve its title, description, image, favicon, and similar metadata. When you open an article in the WebView or an external browser, you connect directly to that website. These connections may send your IP address and device or browser information to the website. The website's own privacy policy applies to its handling of that information.

Opening the feedback form from Settings launches Google Forms in an external browser. Information entered in the form is sent to Google only when you choose to submit it.

4. Purposes of use

• To provide article saving, organization, search, reading, and sharing features
• To understand usage and improve the App's features and usability
• To investigate errors and crashes and maintain quality and security
• To display ads and manage advertising consent
• To respond to feedback and evaluate future improvements

5. Third-party services

The App uses the following third-party services:

• Firebase Analytics analyzes usage such as screen names, action types, search query length, and result counts.
• Firebase Crashlytics collects crashes, errors, and device, OS, and app information for troubleshooting.
• Firebase Remote Config delivers configuration values such as feedback form URLs.
• Google Mobile Ads and User Messaging Platform are used to display and measure ads, prevent fraud, and manage consent based on your region. The data collected varies with your location, consent, device settings, and advertising settings.
• Google Forms is opened in an external browser from the App and receives feedback that you choose to submit. Do not enter personal information, passwords, or other sensitive information in the form.

For Google's handling of information, see the Google Privacy Policy and How Google uses information from sites or apps that use its services.

6. Disclosure to third parties

The Operator does not sell collected information to third parties without your consent, except where required by law. Information may be sent to the service providers listed above as necessary to provide their functions. The Operator reviews their published contractual and privacy information and uses services that are required to provide protections equivalent to those described in this Policy.

7. Retention and deletion

• On-device information is retained until you delete it or uninstall the App.
• Information in the iOS shared container is removed from the processing queue after import.
• Feedback is deleted when it is no longer needed after its purposes have been fulfilled.
• Information held by service providers follows their policies and configured retention periods.

To request access to or deletion of information held by the Operator, contact the address below. Because the App has no user accounts, the Operator may be unable to associate a particular user with anonymous or pseudonymous data held by a service provider.

8. Your choices

Depending on your region and consent status, “Ad privacy options” may appear in the App's settings. You can use it to review or change your advertising choices. You may also use your device's privacy and advertising settings.

9. Security

The Operator takes reasonable safeguards against unauthorized access, loss, destruction, alteration, or disclosure of handled information. However, no internet transmission can be guaranteed to be completely secure.

10. Children's privacy

The App is not primarily directed to children and does not intentionally collect children's personal information. Children should use the App under the supervision of a parent or guardian.

11. Changes to this Policy

This Policy may be updated when the App, its service providers, or applicable requirements change. Material changes will be announced on this page or through an appropriate notice in the App.

12. Contact

Operator: Hikaru Yamaguchi
Email: hikaruyama1999@gmail.com