Privacy Policy

Last updated: May 21, 2026

CalcStak ("the app") is published by Joel Rosinbum ("we", "us"). This policy explains what data the app does and does not handle.

Short version

The app does not collect, transmit, sell, or share any personal data. It does not contact any servers we run, and it does not contact third-party servers. Settings and calculation history are stored only on your device.

What we do not do

• We do not collect personal information of any kind.
• We do not use analytics, telemetry, or crash reporting that leaves your device.
• We do not include third-party advertising, tracking, or attribution SDKs.
• We do not access your contacts, photos, location, microphone, camera, health data, or biometrics.
• We do not use Apple's Advertising Identifier (IDFA) or App Tracking Transparency.
• We do not transmit your calculations, history, or preferences off your device.

What stays on your device

The app stores the following locally, using Apple's standard on-device storage (UserDefaults and the app sandbox). None of this leaves your device:

• Your preferences (angle mode, number format, theme).
• Your calculation history (up to the most recent 150 entries).
• Standard iOS app caches managed by the operating system.

You can clear all of this at any time by deleting the app, or via the Settings tab inside the app.

In-app purchases

The app offers an optional one-time in-app purchase ("Scientific pack") which is processed entirely by Apple's App Store. We do not see your payment information. Apple's privacy policy applies to that transaction.

Children's privacy

The app is rated 4+ and is appropriate for users of all ages. We do not knowingly collect any data from any user, including children under 13.

Apple's role

Apple may collect aggregate data about app usage (downloads, crashes, OS version) under their own privacy policy at apple.com/legal/privacy. This is separate from our app and we have no access to identifiable data about you.

Changes to this policy

If we ever change what the app does — for example, adding optional iCloud sync — we will update this page and update the date at the top. The policy in effect at the time you use the app is the one that applies.

Contact

Questions about this policy: privacy@rosinbum.org.