Privacy Policy

Effective October 2, 2026

CalBook is a calculator app for iPhone. This policy explains what information the app handles. The short version: CalBook runs entirely on your device, and we do not collect, store, or transmit your personal data.

Information we collect

None. CalBook does not have a backend server, user accounts, sign-in, or analytics. Your calculations, sheets, comments, and settings are stored locally on your device and are never sent to us or to any third party.

Purchases

CalBook offers an optional one-time in-app purchase, “CalBook Pro,” processed by Apple’s App Store using StoreKit. Apple handles the transaction, payment information, and receipt. CalBook only sees whether the Pro entitlement is active on your device — it does not see your name, email, payment method, or any other purchase details. Apple’s handling of your purchase is governed by Apple’s privacy policy, available at apple.com/legal/privacy.

Sharing sheets

CalBook lets you share individual sheets as text, an image, a PDF or CSV file, or a share link, using iOS’s built-in share sheet. When you choose to share, the content goes only to the destination you pick (Messages, Mail, Files, etc.). Share links carry the sheet’s contents inside the link itself and open directly in CalBook on the recipient’s device; CalBook does not upload your sheets to any server.

Third-party services

CalBook does not include any third-party analytics, advertising, tracking, or crash-reporting SDKs.

Children’s privacy

CalBook is suitable for general audiences and does not knowingly collect information from anyone, including children under 13.

Changes to this policy

If this policy changes in a meaningful way, we’ll update the effective date at the top of this page. Material changes will be reflected in a new release of the app.

Contact

Questions about this policy? Email dericktsangwork@gmail.com.