Last updated: August 30, 2026
These Terms of Use ("Terms") govern your use of the mobile application Twin Calc ("the App"), provided by Hiroki Sugiyama ("we", "us"). By downloading or using the App, you agree to these Terms.
We grant you a personal, non-exclusive, non-transferable, revocable license to use the App on Apple-branded devices that you own or control, for your personal or professional use, subject to these Terms and the Apple App Store Terms of Service.
The App offers a one-time, non-consumable "PRO" purchase that unlocks additional features. Purchases are processed by Apple and are subject to the App Store's terms. You can restore a previous purchase using the "Restore purchase" option. Except as required by law or App Store policy, purchases are non-refundable.
The App is a general-purpose calculator. While we strive for accuracy, results may be affected by rounding and display limits. You are responsible for verifying any result before relying on it for financial, legal, medical, or other important decisions.
The App is provided "as is" and "as available" without warranties of any kind, whether express or implied, including but not limited to fitness for a particular purpose. We do not warrant that the App will be uninterrupted or error-free.
To the maximum extent permitted by law, we shall not be liable for any indirect, incidental, special, or consequential damages arising out of or related to your use of the App, including any loss of data or any loss resulting from reliance on a calculation.
These Terms are governed by the laws of Japan, without regard to its conflict-of-law provisions.
We may update these Terms from time to time. The latest version will always be available at this page.
For questions about these Terms, contact us at hiroki.sugiyama.dev@gmail.com.