Terms of Service
These Terms govern your use of the Chess Shield iOS app and the website at chessshield.com (collectively, the "Service"), operated by Alejandro Treviño Saldaña, an independent developer based in Monterrey, México ("Chess Shield", "we", "us"). By downloading, installing, or using the Service, you agree to these Terms. If you don't agree, don't use the Service.
1. What Chess Shield is
Chess Shield is an iOS app that lets you block selected apps on your iPhone behind chess puzzles calibrated to your rating. We provide the app, the puzzle content (sourced from the open Lichess puzzle database), and the rating algorithm. We do not provide a network service, an account system, or a server-side backup of your data.
2. License
Subject to these Terms, we grant you a personal, non-transferable, non-exclusive, revocable license to install and use the Chess Shield iOS app on devices that you own or control, for your personal, non-commercial use. You may not:
- copy, modify, reverse-engineer, decompile, or attempt to extract the source code of the app, except as expressly permitted by applicable law;
- sublicense, sell, rent, or lease the app to anyone else;
- use the Service to violate the rights of others, infringe intellectual property, or break any law;
- circumvent or attempt to circumvent rate limits, access controls, or the in-app purchase system.
3. Subscriptions, billing, and refunds
Chess Shield Pro is available as an auto-renewing subscription processed by Apple through the App Store. Pricing and renewal terms (monthly $4.99 USD, yearly $39.99 USD, with a 7-day free trial on the yearly plan for new subscribers) are presented before purchase and may vary by region. Apple converts pricing to your local currency.
- Subscriptions auto-renew at the end of each period unless you cancel at least 24 hours before the renewal date.
- Manage or cancel your subscription in iOS Settings → your name → Subscriptions.
- Refunds are issued by Apple, not by Chess Shield. Request refunds at reportaproblem.apple.com.
- If your subscription ends, the app reverts to the Free tier. Your local progress data is preserved.
4. Family Controls and blocking behavior
Chess Shield uses Apple's Family Controls framework to block the apps you choose. The block is enforced by iOS itself, not by our servers. You decide which apps to add to the shield and which mode (Quick, Standard, Long) to use. You can disable the shield at any time in the app.
Chess Shield does not promise that the block is uncircumventable. iOS Family Controls is a strong but not absolute barrier, and Apple may change its behavior in OS updates. We do not guarantee any specific reduction in your screen time.
5. Puzzle content
Puzzles are derived from the Lichess open puzzle database (database.lichess.org), released by Lichess under the Creative Commons CC0 license. Chess Shield curates a subset, scores each solve with a Glicko-2 implementation, and applies its own theme labels and pedagogy copy. The puzzle data itself remains free for any use under CC0.
6. Disclaimers
The Service is provided "as is" and "as available", without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, non-infringement, accuracy, or uninterrupted operation. We do not warrant that your rating estimate is accurate to any external chess rating system, that the puzzle calibration will produce specific improvement, or that the shield will prevent any specific behavior.
7. Limitation of liability
To the maximum extent permitted by law, Chess Shield is not liable for any indirect, incidental, consequential, special, or punitive damages, including loss of data, lost profits, or device damage, arising from your use of the Service. Our total cumulative liability for any claim arising from the Service will not exceed the greater of (a) the amount you paid for the Service in the 12 months preceding the claim, or (b) USD $50.
8. Termination
You may stop using the Service at any time by uninstalling the app. We may suspend or terminate the Service, in whole or in part, at any time, for any reason, including violations of these Terms.
9. Changes
We may update these Terms occasionally. When we do, we'll update the "Last updated" date above. Material changes will be surfaced in-app where feasible. Continued use after a change constitutes acceptance.
10. Governing law
These Terms are governed by the laws of México, without regard to conflict-of-laws principles. Any dispute that cannot be resolved informally will be subject to the exclusive jurisdiction of the courts of Monterrey, Nuevo León, México. If you are a consumer accessing the Service from outside México, mandatory consumer-protection laws of your country of residence apply notwithstanding this clause.
11. Apple-specific terms
Because the app is distributed through the Apple App Store, the following also applies: these Terms are between you and Chess Shield only, not Apple. Apple is not responsible for the app or its content. Apple has no obligation to provide support or maintenance. In the event of any failure of the app to conform to any applicable warranty, you may notify Apple, and Apple will refund the purchase price; to the maximum extent permitted by law, Apple has no other warranty obligation. Apple and its subsidiaries are third-party beneficiaries of these Terms and, upon your acceptance, have the right to enforce them against you.
12. Contact
Questions about these Terms: hello@chessshield.com.
Support: support@chessshield.com.