Privacy Policy

Effective 27 August 2026

Sumi is a scientific calculator for iPhone and Android made by Tomu Ozawa. This policy explains what the app does and does not do with your data. The short version: Sumi collects no personal data and makes no network requests of its own.

Data stored on your device

Sumi keeps your calculation history, memory values and settings in the app's private storage on your device so they are there the next time you open it. This information is never sent anywhere. You can clear it at any time with Reset all in the settings sheet, and it is removed when you delete the app.

Tip jar purchases

Sumi is free. If you choose to leave a tip, the purchase is processed entirely by Apple (through the App Store) or Google (through Google Play). Sumi receives only a confirmation that the purchase succeeded; it never sees your name, email address, or payment details. Apple's and Google's handling of purchase data is described in the Apple Privacy Policy and the Google Privacy Policy.

Third-party services

Sumi contains no analytics, advertising, or crash-reporting software, and no third-party code other than the platform billing libraries needed for the tip jar.

Children

Sumi is suitable for a general audience. Because it collects no data from anyone, it collects no data from children.

Changes to this policy

If Sumi's behaviour changes in a way that affects your privacy, this page will be updated and the effective date above revised.

Contact

Questions about this policy can be sent to hello@sumicalculator.com.