BunNote Privacy Policy

BunDev ("we" or "us"), an independent developer, has established this Privacy Policy regarding the handling of user information in the application "BunNote" ("the App").

1. Basic Policy

We place the highest priority on protecting user privacy. We never collect any information entered by users, and data is, as a rule, stored only on the user's own device. The single exception is a feature that, only when you turn it on yourself, saves an encrypted backup to your own Google Drive (Section 4). That backup never passes through our servers, and no third party — including us — can read its contents. We use no analytics SDKs, no advertising SDKs, and no crash reporting services.

2. Data Storage and Encryption

The content of your notes is encrypted using AES-256 (SQLCipher) with a key derived from your master password, and stored on your device (if you use the backup described in Section 4, an encrypted copy is also stored in your own Google Drive). Your master password is never stored in plain text, neither on our servers nor on your device. It is technically impossible for us or any third party — including the developer — to access this data.

3. Information Stored on Your Device

The following is stored on your device and is never transmitted to our servers.

• Memo Data: Bank account details, passwords, identification information, schedules, etc. entered in the App are stored in encrypted form on your device only (SQLCipher-encrypted Room database).
• Settings Data: Theme color, display settings, reminder settings, etc. are stored on your device (DataStore).
• Scheduled Notifications: So that reminders can be re-registered after a device restart without your master password, the title and time of each note that has a reminder are stored unencrypted in the App's private storage area on your device. They are not accessible to other apps and are never transmitted externally. They are deleted when you turn the reminder off or delete the note. Note that the notification itself displays the note's title.
• Widget Display Data: To show calendar markers on the home screen widget, the App stores only the dates and categories of your scheduled items on your device. No titles or note content are stored. This information is used solely to draw the widget and is never transmitted externally.
• Wallpaper Images: An image set as a watermark wallpaper is copied into the App's private storage area on your device. It is not accessible to other apps and is never transmitted externally.
• Attached Images: Images you attach to a note (chosen from your gallery or taken with the camera) are reduced in size when they exceed a set limit (4 megapixels) to save space, and are then stored encrypted, together with their thumbnails, in the App's private storage area on your device. The encryption key is generated randomly and kept inside the encrypted note database. They are not accessible to other apps and are never transmitted externally (except in the backup described in Section 4). A photo taken with the camera is placed in the App's private temporary area only while it is being taken in, and is deleted immediately afterwards. Because photos are taken with your device's camera app, that camera app may keep its own copy depending on its settings.
• Backup Data (Export to File): Exporting to a file is entirely user-initiated. The exported file remains encrypted, and you choose where it is saved. It is never sent to our servers. Restoring a backup requires the master password that was in use when the backup was created. For backups to Google Drive, see Section 4.

4. Backup to Google Drive

To prepare for a new phone or a broken one, the App can back up your data to your own Google Drive. This feature works only when you use it yourself; by default nothing is sent.

• What is saved: A single file containing the note database, settings, wallpaper images and attached images. Everything in it is encrypted before it is sent (the database, settings and wallpapers with a key derived from your master password; attached images with the key kept inside the database). It never passes through our servers, and no third party — including us and Google — can read its contents.
• Where it is saved: A folder named "ないしょメモ" in your own Google Drive. A backup you save manually (for moving to a new phone) is kept as a single, latest file and is replaced each time you save.
• Daily automatic backup: Only if you turn it on, the App saves a backup once a day when you unlock it. To avoid using mobile data, it runs only while you are connected to Wi-Fi (a manual save works on any connection). Up to the three most recent are kept; older ones are deleted. It is off by default.
• Access to your Google Account: Only after you grant permission on Google's authorization screen, the App uses the Google Drive drive.file scope, which allows access only to files the App itself has created. The App does not access or obtain your other files, email address, name, contacts or any other account information. The access token is used only temporarily on your device and is neither stored nor sent anywhere else.
• Limited use: Information received from Google APIs is used only to save, list and restore backups and to delete older backups. It is not used for any other purpose and is never shared with third parties. The App's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.
• Deletion and revoking access: Because backups are in your own Google Drive, you can delete them from Google Drive at any time. Uninstalling the App does not automatically delete backups in Google Drive. You can revoke the App's access at any time from "Third-party apps & services" in your Google Account.
• What you need to restore: The same Google Account used to create the backup, and the master password that was in use when the backup was created.

5. Permissions

The App uses the following permissions to provide its features. Information obtained is never shared with third parties.

• Internet (INTERNET): Used solely for communication with Google Play Billing to purchase and restore the Pro Plan, and, if you use it, for backing up to and restoring from Google Drive (Section 4). We never collect any personal user data.
• In-app Billing (com.android.vending.BILLING): To purchase and restore the Pro Plan through Google Play.
• Biometric (USE_BIOMETRIC / USE_FINGERPRINT): For unlocking the App using fingerprint or face authentication. Biometric data itself is managed by the Android OS and is never accessed or stored by the App.
• Notifications (POST_NOTIFICATIONS): To send reminder notifications.
• Exact Alarm (SCHEDULE_EXACT_ALARM): To trigger reminders at the exact scheduled time.
• Boot Completed (RECEIVE_BOOT_COMPLETED): To automatically restore reminder schedules and widget display after a device restart.
• Network State (ACCESS_NETWORK_STATE): To limit the daily automatic backup to Wi-Fi, the App checks only whether the current connection is metered (such as mobile data).

Choosing wallpapers and attached images uses the Android system photo picker, so the App does not request access to your photo library. It can only handle the images you explicitly select. Photos are taken with your device's camera app, so the App does not hold the camera permission.

6. Crash Records and Bug Reports

We do not use Firebase Crashlytics or any other crash reporting service. If the App terminates unexpectedly, a diagnostic record (exception type, class name, method name and line number) is saved on your device only. This record contains no note content, no master password and no file paths.

The in-app "Report a Bug" feature sends an email only after you review that record on screen and choose to send it. No automatic transmission ever occurs.

7. Third-Party Services

Google Play Billing (Payments)
The App uses Google Play Billing for the Pro Plan. Payment information is managed by Google, and we do not have access to payment details. We only receive whether a purchase has been completed.

Google Drive / Google Play services (Backup)
For the backup described in Section 4, the App uses the Google Drive API and the authorization provided by Google Play services. Backups are encrypted before they are sent, so Google cannot read their contents. Google's Privacy Policy applies to your Google Account and Google Drive.

We do not use any advertising SDKs, analytics SDKs, crash reporting services, or any other third-party SDKs beyond the above.

8. Children

The App is not directed at any particular age group and does not collect personal information from users of any age.

9. Changes to This Policy

We may update this Policy. Any significant changes will be posted on this page.

10. Contact