Last updated: July 12, 2026
This Privacy Policy describes how the iOS app "Kotodute" (Japanese name: コトヅテ, the "App"), provided by Toshinori Matsui (the "Developer"), handles user information.
1. Core principle: the Developer collects no data
The App has no server operated by the Developer. All data you register in the App (messages, recipients, settings, etc.) is stored only inside your own Google account (a spreadsheet in your Google Drive). The Developer never receives, collects, stores, or views any of this data — it is technically impossible.
2. Information the App handles and where it is stored
| Information | Stored in | Purpose |
|---|---|---|
| Messages (subject, body, attachment links) | A sheet in your Google Drive | Delivering them to recipients by email when triggered |
| Recipients' and confirmers' names and email addresses | A sheet in your Google Drive | Message delivery and safety confirmation |
| Check-in dates and watch settings | A sheet in your Google Drive | Monitoring for missed check-ins |
| Your Google account email address | Your device | Showing the connected account, receiving reminder emails, and deriving the encryption key |
| Authentication tokens | Your device (Keychain) | Connecting to Google APIs |
Message subjects, bodies, attachment links, and recipients' names and email addresses are encrypted by the App before being saved to the sheet.
3. Google account permissions (OAuth scopes) and their use
- Basic info (openid, email): To identify the connected Google account and display it in the App.
- Google Drive (drive.file): To create, read, write, and delete the single watch spreadsheet the App creates. The App cannot access any files other than those it created.
- Apps Script (script.projects / script.deployments): To install and update the watch program (a fixed script bundled with the App) inside your own spreadsheet. The program runs only within your account.
These permissions are used solely for the purposes above. No data obtained through them is ever transmitted to the Developer or any third party. Kotodute's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
4. About email sending
Reminder emails, safety-confirmation emails, and your messages are all sent from your own Google account (by the watch program installed in your spreadsheet). The Developer neither sends emails nor can view their contents.
5. Third parties, analytics, and advertising
- The Developer never provides your data to third parties (the Developer holds no data in the first place).
- The App uses no analytics tools, advertising SDKs, or tracking technologies.
- In-app purchases (Premium) are processed by Apple. The Developer never receives payment details such as credit card numbers.
6. Deleting your data
You can delete your data at any time:
- App Settings → Delete the watch sheet: Completely deletes the spreadsheet the App created (including all messages and recipients) and the watch program from your Google Drive.
- Sign out: Erases credentials and data from your device.
- Revoke access from your Google account: You can revoke the App's access at any time from "Third-party apps & services" in your Google account.
Additionally, once your messages have been delivered (triggered), the messages and recipients are automatically deleted from the sheet to protect your privacy.
7. Children's privacy
The App is not directed at children under 13, and it does not knowingly collect information from children.
8. Changes to this policy
This policy may be revised in response to legal changes or new features. Material changes will be announced on this page and in the App.
9. Contact
For inquiries about this policy or how the App handles information, please contact:
Developer: Toshinori Matsui
Email: blesimlinker.help@gmail.com