Terms of use

Effective and last updated: October 7, 2026

These terms govern Caltrilo (the “service”), provided by Suzushinlab (the “operator”). Please review these terms and the privacy policy before using the service.

1. Service description

The service provides game analysis, puzzle generation, spaced repetition, Woodpecker practice, and related chess learning tools. Analysis supports learning and does not guarantee fully accurate best moves, improved results, or any particular outcome.

2. Conditions of use

You are responsible for your device and connection and for complying with external providers’ terms. Minors must obtain any legally required guardian consent, including for paid purchases. You must have the necessary rights to use games and other data you import.

3. Free, Pro, and payments

Free includes unlimited game analysis and 5 training positions per day across spaced repetition and Woodpecker. Pro is a paid subscription that removes this training limit. Prices, currency, taxes, total charges, billing cycles, and renewal terms are shown at checkout. Polar’s purchase terms apply to paid contracts and payments. Pro access requires verification of the license key supplied after purchase.

4. Renewal, cancellation, and refunds

Paid subscriptions renew automatically under the terms shown at purchase. Cancel through Polar’s portal using “Manage subscription” in the app. The effective cancellation date and remaining access period follow the terms displayed there. Removing a local license or deleting data does not cancel a subscription. For refunds, follow the instructions provided by Polar at purchase. Eligibility depends on applicable law, purchase terms, Polar’s procedures, and individual circumstances. These terms do not limit statutory rights.

5. License management

Keep your license key secure. Do not publish, resell, or improperly share it. Verification uses a network connection. A verified temporary cache may allow limited continued access, but expiration, revocation, or cache expiry returns the app to Free. Register and verify your license in each browser you use.

6. Data management

Games and training history are generally stored locally without automatic sync between devices. Make backups as needed. Browser storage removal, device failure, and configuration changes may cause data loss. The operator cannot restore local data. Rights in your data remain with you or its rightful owners.

7. Prohibited conduct

• Conduct that violates applicable law, public order, or these terms.
• Unauthorized access, excessive API requests, or interference with service operation.
• Improperly bypassing license verification or misusing another person’s payment details or license.
• Infringement of intellectual property, privacy, or other third-party rights.
• Using the service for prohibited assistance during live games in violation of a chess platform’s rules.

8. Intellectual property and external services

Rights in the service’s design, text, software, and other materials belong to the operator or rightful owners. Third-party software, including Stockfish, is governed by its own licenses. Integrations with Chess.com, Lichess, Polar, and other providers may become unavailable following their changes or outages. This is not an official Chess.com or Lichess service.

9. Changes, interruptions, and restrictions

Maintenance, outages, or external service interruptions may require changes or suspension. We may reasonably restrict access in response to violations or misuse. We will provide advance notice where possible for major changes to or termination of paid features and handle affected users according to applicable law and purchase terms.

10. Liability

We aim to provide a reliable service but do not guarantee uninterrupted or error-free operation. Except in cases of intentional misconduct, gross negligence, or where applicable law prohibits a limitation, liability is limited to ordinary and direct damages. Any exclusion or limitation that conflicts with mandatory law, including Japan’s Consumer Contract Act, does not apply.

11. Changes to terms and governing law

We may amend these terms in accordance with law. Significant changes and their effective date will be announced in the service. Japanese law governs these terms without excluding mandatory protections under the laws of your place of residence. We will first seek to resolve disputes through good-faith discussion.

12. Contact

Contact form on the creator’s blog is available for support. Please do not include card information or license keys. Use the channels provided by Polar for private payment or refund details.