Effective Date: November 4, 2026

1. Information We Collect

None. Willis15C does not collect any personal information, usage statistics, crash reports, or analytics of any kind. The application has no backend server and does not phone home.

2. Your Calculator Data

Like a calculator with continuous memory, Willis15C saves its state automatically so it is always where you left it:

• Your stack, storage registers, programs, matrices, flags, and display modes are stored in a local file on your device.
• A few interface preferences, such as whether the stack panel is open and whether key haptics are on, are stored in your device’s standard app settings.
• All calculation happens on your device. None of this data is uploaded to, copied to, or stored on any server we operate.
• Willis15C does not need an internet connection for anything, and it has no sync feature of its own.

3. Clipboard

Willis15C uses your system clipboard only when you ask it to. Choosing Copy places a number on the clipboard, and choosing Paste reads the clipboard to bring a number in. The app does not read the clipboard at any other time. If you use Apple’s Universal Clipboard, your operating system may make what you copy available on your other devices; that is an Apple feature under your control, and the content never reaches us.

4. Device Permissions

Willis15C does not ask for access to your camera, microphone, location, contacts, photos, or files. Key haptics on iPhone are produced on the device and can be turned off in the app.

5. Backups

Willis15C does not back up or sync your data itself. If you use a device backup such as iCloud Backup, a Finder backup, or Time Machine, your operating system may include the app’s saved state along with the rest of your device. Those backups belong to you and are governed by the service you use for them. We have no access to them.

6. Deleting Your Data

Your data stays on your device, so deleting it is in your hands:

• Everywhere: Reset Calculator clears your stack, registers, programs, and matrices, and returns the calculator to its starting state.
• iPhone: deleting the app removes its saved state from the device.
• Mac: macOS keeps an app’s saved data when the app is moved to the Trash, so choose Reset Calculator first if you want the saved state cleared as well.

Copies in any device backup you have made remain until that backup is removed.

7. Telemetry and Analytics

Willis15C does not include any telemetry, analytics, or crash-reporting frameworks. We do not track how you use the application, which features you access, how often you use it, or any other behavioral data.

8. Tracking and Advertising

Willis15C does not use cookies, tracking pixels, advertising identifiers, fingerprinting, or any other tracking technologies. We do not display advertisements and we do not participate in any advertising networks.

9. Purchases and the App Store

Willis15C is distributed through Apple. Apple handles the purchase or download and may collect transaction and account information as part of that process. This data is collected and managed by Apple, not by us. See the Apple Privacy Policy for details.

We do not receive, store, or have access to your payment information, Apple Account, or any other account credentials.

Apple gives developers aggregated sales and download figures. If you choose to share analytics with app developers in your device settings, Apple may also provide us with crash reports and usage figures. These come from Apple under its own policies and your own settings; they are not collected by Willis15C itself. If you test a pre-release build through Apple’s TestFlight, Apple shares with us the tester details, crash reports, and feedback that TestFlight provides.

10. Third-Party Services

Willis15C does not integrate with, send data to, or receive data from any third-party services, and it embeds no third-party SDKs. The app is self-contained.

11. Children's Privacy

Because Willis15C does not collect any data from any user, it does not knowingly or unknowingly collect information from children under the age of 13 (or any other age).

12. Your Data Rights

Because Willis15C does not collect, process, or store any personal data on our systems, there is no personal data of yours in the app for us to access, correct, delete, or transfer. Your calculator data exists on your device under your full control, and you can clear it at any time (see “Deleting Your Data” above).

13. Data Security

Since Willis15C does not collect or transmit data, there is no copy of your data on our systems to be intercepted, breached, or exposed. Your saved state is protected by your operating system’s built-in security mechanisms and any encryption you apply at the device level.

14. Changes to This Privacy Policy

We may update this Privacy Policy from time to time to reflect changes in our practices or for legal, regulatory, or operational reasons. Any changes will be posted on this page with an updated effective date.

15. Contact Us

If you have any questions, concerns, or requests regarding this Privacy Policy, please contact us at:

Lacy Digital Labs LLC
Contact us through our support center

Willis15C is original software written from scratch. It contains no third-party firmware or ROM, and Willis15C and Lacy Digital Labs, LLC are not affiliated with, endorsed by, or sponsored by any calculator manufacturer.