SUMFLASH
Terms of Use
Last updated: September 26, 2026
This is a translation of the Japanese original. If there is any discrepancy, the Japanese version prevails.
These Terms of Use (the "Terms") set out the conditions for using the iOS app "Sumflash" (the "App"). By downloading or using the App, you agree to these Terms.
The App is subject to Apple Inc.'s Licensed Application End User License Agreement (Standard EULA). These Terms supplement the Standard EULA; if they conflict, the Standard EULA prevails.
1. The service
The App provides a place to practice flash mental math: adding up numbers that appear on screen one at a time.
2. About results of practice
The App provides a place to practice. It does not guarantee any improvement in calculation, memory, concentration, or other abilities, or success in any test or examination.
3. Advertising
The App is free and shows third-party ads (Google AdMob) to cover its costs (no ads with Premium). The developer is not responsible for ad content or for any dealings with advertisers. For how ad-related data is handled, see the Privacy Policy.
4. Premium (auto-renewable subscription)
- What you get: no ads. Every other feature is free
- Period and price: monthly. The price is shown on the purchase screen in the App
- Renewal: unless canceled at least 24 hours before the renewal date, the subscription renews for the same period and price and is charged to your Apple ID
- Cancellation: cancel anytime in iPhone Settings › Apple ID › Subscriptions. Canceling mid-period does not refund the remaining period (refunds follow Apple's policies)
5. Prohibited conduct
- Copying, modifying, adapting, or creating derivative works of the App
- Reverse engineering, decompiling, or disassembling the App
- Redistributing, lending, or selling the App or any part of it
- Interfering with or altering the display of ads
- Violating laws or public order
- Interfering with the provision of the App
6. Intellectual property
All intellectual property rights in the App, including its program, design, text, and sounds, belong to the developer or the rightful owners.
7. Disclaimer
The App is provided "as is". The developer does not guarantee that the App fits any particular purpose, will be available without interruption, or is free of defects. The developer is not responsible for restoring records stored on your device if they are lost.
Except where liability cannot be excluded by law, the developer is not liable for any damage arising from the use of, or inability to use, the App.
8. Changes to or discontinuation of the App
The developer may change or discontinue the App without prior notice.
9. Changes to these Terms
The developer may change these Terms as needed. Changes take effect when posted on this page.
10. Governing law and jurisdiction
These Terms are governed by the laws of Japan. The Tokyo District Court has exclusive jurisdiction as the court of first instance for any dispute concerning the App or these Terms.
11. Contact
Provider: Toru Fukui