Privacy Policy
1. Information we collect
We do not collect any personal information. Specifically, SmartCalcu does not collect, request or access:
- Identity information such as name, phone number, email address or government IDs (the app has no sign-up or login)
- Location data
- Contacts, call logs, messages or calendars
- Photos or files (the app has no image import feature)
- Device identifiers (IDFA / IMEI / OAID, etc.) or advertising identifiers
- Usage analytics, crash reports or page-view tracking
The formulas you type, the strokes you write and the expressions you speak are used only for that single recognition or calculation. They are never collected by us or stored on any server.
2. System permissions
SmartCalcu requests only the permissions strictly required for its features, and only at the moment you first use the related feature. You may decline; only that specific feature becomes unavailable, while everything else keeps working.
| Permission | Purpose | Required? |
|---|---|---|
| Microphone | Records audio only while you tap the microphone button, to turn a spoken expression into formula text | No — voice input is unavailable if declined |
| Speech recognition (iOS / macOS) |
Uses the operating system's speech recognition capability to convert speech into text | No — voice input is unavailable if declined |
| Network access (Android) |
Used only by the system speech recognition service when it needs it; handwriting recognition and calculation never use the network | No |
The app never records audio silently in the background. Recording occurs only while the voice input interface is actively listening, and stops as soon as recognition ends.
3. Data storage and transmission
3.1 Local processing
Handwriting recognition uses an offline model bundled with the app and runs inference locally on your device. Formula parsing and evaluation are handled by the app's built-in engine. Both features require no network at all, and your strokes and formulas never leave your device.
3.2 Local storage
So that the offline recognition model can be loaded correctly, the app may copy the bundled model files into its own private directory. That directory is protected by the operating system sandbox and is inaccessible to other apps. The files are removed when you uninstall the app.
3.3 About network use for voice input
Speech recognition is performed by the speech recognition service built into your operating system (Apple speech recognition on iOS/macOS, the system speech recognition service on Android, the system speech service on HarmonyOS). Depending on your OS version and settings, that service may run on-device or in the OS vendor's cloud. This process is handled directly by the operating system; we neither participate in it nor have access to the audio. Such processing is governed by the respective OS vendor's privacy policy. If you prefer that no network activity occur at all, simply do not use voice input and use the keypad or handwriting instead.
3.4 What we do not do
- No user accounts, no user profiling
- No selling, renting or sharing of data with any third party
- No advertising, no ad SDKs
- No in-app purchases, no access to payment information
4. Third-party components
All third-party components in the app are integrated as local libraries and transmit no data:
| Component | Purpose | Network? |
|---|---|---|
| ONNX Runtime | Runs the handwriting recognition model on-device | No |
| Flutter | Cross-platform UI framework | No |
| System speech recognition | Speech-to-text (only while you use voice input) | Depends on the OS |
The app integrates no advertising, push notification, analytics or social sharing SDKs.
5. Children's privacy
SmartCalcu is suitable for users of all ages, including students. Because the app collects no personal information and has no social features, no user-generated content display, no advertising and no in-app purchases, no collection of children's personal information takes place. We do not knowingly collect personal information from users of any age. If you are a parent or guardian with privacy questions, please contact us at the address below.
6. Your rights
Because we hold none of your personal data, there is nothing for us to look up, correct or delete on your behalf. You have full control over local data:
- Revoke microphone / speech recognition permissions in system settings at any time
- Clear the current formula and handwriting whiteboard inside the app
- Uninstall the app to delete all local files it created
If you believe your rights are affected, or you would like us to explain how data is handled, email us at the address below. We will respond within 15 business days.
7. Data security
The app runs inside the sandbox provided by the operating system, and the files it creates are accessible only to the app itself. Because there is no upload and no server-side storage, there is no server-side data breach risk.
8. Changes to this policy
If a change in app functionality requires revising this policy, we will update the "Last updated" date at the top of this page. For material changes — such as adding a feature that requires collecting information — we will present a prominent notice inside the app. Continued use of the app constitutes acceptance of the updated policy.
9. Contact us
See the Support page for other ways to reach us.