Last updated: 2026-10-25
Privacy Policy
Last updated: October 25, 2026
MiFormulas is a personal note app for writing and keeping math formulas together with text. It has no app account, no developer server, no analytics, and no ads. All notes are stored on your device, and the developer cannot see them.
1. Data Stored by the App
The app stores only the following, in its own storage on your device:
| Data | Purpose |
|---|---|
| Notes (title, body, created and updated time) | Saving, searching, and sorting notes |
| Whether Premium has been purchased | Keeping Premium available when the store cannot be reached |
| Time of the last backup | Showing it in Settings to encourage backups |
We do not collect personal information such as your name or email address, location, device IDs, usage data, or crash reports. We do not track you.
2. Data That Leaves Your Device
The app never sends your notes off your device. Data leaves the device only in these cases:
- Purchases: To purchase Premium or restore a purchase, the app connects to the App Store (iOS) or Google Play (Android). Payment information is handled by Apple / Google
- OS backups: If iCloud Backup (iOS) or Android Auto Backup is turned on in the device settings, your notes are backed up to your own Apple / Google account. This is a feature of the OS, and the developer cannot access it
- Backup files: Create backup in Settings saves all notes as a JSON file and hands it to a place you choose. Neither the app nor the developer receives the file
- Feedback email: Send feedback in Settings only opens a draft to the developer in your mail app. The end of the draft includes the app and OS versions, which you can delete before sending. Emails you send are used only to respond to you and to improve the app
The privacy policies of Apple and Google also apply to purchases and backups.
We do not share data with third parties.
3. Buyer Information
The developer does not collect buyers' personal information in the app. On Google Play, however, the developer may be able to see a buyer's email address and similar details in the Google Play Console, for handling refunds and orders. On the App Store, the developer receives no information that identifies individual buyers.
4. Deleting and Exporting Data
- Deleting a note: The note is deleted right after you confirm, and cannot be restored
- Deleting the app: All data on the device is deleted. Data in OS backups can be deleted from each OS's settings
- Exporting: Settings → Data → Create backup exports all notes to a JSON file. When restoring, you can choose to Merge with or Replace your current notes
5. Children's Privacy
The app collects no personal information, so it collects none from children of any age.
6. Changes to This Policy
When this policy changes, we update this page and record the change in "8. Policy Version History".
7. Contact
For questions about privacy or security, or to report a security issue, please contact:
support (at) netplan.co.jp
8. Policy Version History
| Version | Date | Changes |
|---|---|---|
| 1.1 | 2026-10-25 | Rewritten more concisely (no change in how data is handled) |
| 1.0 | 2026-10-25 | Initial release |