Terms of Service

Last updated: March 2026

Welcome to Derstina. These Terms of Service ("Terms") govern your access to and use of the Derstina platform, website, and services available at derstina.com ("Service"). By creating an account or using our Service, you agree to be bound by these Terms. If you do not agree, please do not use the Service.

1. Definitions

"Derstina" (also "we," "us," or "our") refers to the Derstina platform and its operators. "Teacher" or "User" refers to any individual who creates an account on Derstina to manage lessons and students. "Student" refers to any individual who accesses content through a Teacher's shared portal link. "Content" refers to lesson plans, games, flashcards, quizzes, and all other materials provided through the Service.

2. Eligibility and Account Registration

You must be at least 18 years old (or the age of majority in your jurisdiction) to create a Derstina account. By registering, you agree to provide accurate, current, and complete information. You are responsible for maintaining the confidentiality of your account credentials and for all activities that occur under your account.

You agree to:

• Provide truthful and accurate registration information
• Keep your login credentials secure and not share them with others
• Notify us immediately at support@derstina.com if you suspect unauthorized access to your account
• Accept responsibility for all activity that occurs under your account

3. The Service

Derstina is a software-as-a-service (SaaS) platform designed for English as a Second Language (ESL) teachers. The Service provides ready-to-use lesson plans, interactive games, flashcards, quizzes, student management tools, and a student portal. Teachers create accounts and manage student data within the platform. Students access assigned content through shared portal links and are not required to create accounts.

4. Subscription Plans and Billing

Derstina offers the following paid subscription plans:

4.1 Free Trial

All plans include a 30-day free trial. During the trial period, you have full access to the features of your chosen plan. A valid payment method is required to start a trial. If you do not cancel before the trial ends, your subscription will automatically convert to a paid plan and your payment method will be charged.

4.2 Recurring Billing

Subscriptions are billed on a recurring basis (monthly or annually, depending on the billing cycle you select). By subscribing, you authorize Derstina to charge your payment method at the beginning of each billing cycle. All payments are processed securely through Stripe, our third-party payment processor.

4.3 Cancellation

You may cancel your subscription at any time through your account settings. Upon cancellation, you will retain access to the Service for the remainder of your current billing period. No refunds are provided for partial billing periods. If you cancel during your free trial, you will not be charged.

4.4 Plan Changes

You may upgrade or downgrade your plan at any time. Upgrades take effect immediately with prorated billing. Downgrades take effect at the start of your next billing cycle.

4.5 Price Changes

We reserve the right to modify pricing. Any price changes will be communicated to you at least 30 days in advance and will apply at the start of your next billing cycle following the notice period.

5. Acceptable Use

You agree to use the Service only for lawful purposes and in accordance with these Terms. You shall not:

• Use the Service for any illegal, fraudulent, or harmful activity
• Upload, transmit, or distribute content that is defamatory, obscene, or otherwise objectionable
• Attempt to gain unauthorized access to any part of the Service, other accounts, or related systems
• Reverse-engineer, decompile, or disassemble any part of the Service
• Use automated scripts, bots, or scrapers to access or collect data from the Service
• Resell, redistribute, or sublicense the Service or its content without our prior written consent
• Interfere with or disrupt the integrity or performance of the Service
• Use the Service in any manner that could damage, disable, or impair our infrastructure

6. Intellectual Property

All content, materials, and resources available on or through the Service — including but not limited to lesson plans, games, flashcards, quizzes, text, graphics, logos, and software — are the exclusive property of Derstina or its licensors and are protected by applicable intellectual property laws.

Your subscription grants you a limited, non-exclusive, non-transferable, revocable license to access and use the Content solely for your personal or professional ESL teaching activities. You may not reproduce, distribute, modify, create derivative works from, or publicly display any Content outside of the intended use within the Service, unless expressly authorized in writing by Derstina.

Any content you create or upload to the platform (such as custom decks or student notes) remains your property. However, by uploading content, you grant Derstina a limited license to store, process, and display that content as necessary to provide the Service.

7. Student Data and Privacy

As a Teacher, you may input and manage student information within the Service, including names, proficiency levels, and learning progress. You acknowledge that you are responsible for ensuring that you have the appropriate consent or legal basis to provide any student data to the Service.

Students access the platform through shared portal links and do not create accounts. Derstina collects minimal data from students as described in our Privacy Policy.

We take data protection seriously. For full details on how we collect, use, store, and protect personal data, please refer to our Privacy Policy.

8. Service Availability

We strive to maintain high availability of the Service, but we do not guarantee uninterrupted, error-free, or secure access. The Service is provided on an "as is" and "as available" basis. We may temporarily suspend access for maintenance, updates, or circumstances beyond our control without prior notice.

We reserve the right to modify, update, or discontinue any feature or aspect of the Service at any time. We will make reasonable efforts to notify users of significant changes.

9. Limitation of Liability

To the maximum extent permitted by applicable law, Derstina and its officers, directors, employees, and agents shall not be liable for any indirect, incidental, special, consequential, or punitive damages, including but not limited to loss of profits, data, use, or goodwill, arising out of or in connection with your use of or inability to use the Service.

In no event shall our total aggregate liability exceed the amount you have paid to Derstina in the twelve (12) months preceding the event giving rise to the claim.

Some jurisdictions do not allow the exclusion or limitation of certain damages. In such jurisdictions, our liability shall be limited to the greatest extent permitted by law.

10. Disclaimer of Warranties

The Service is provided "as is" and "as available" without warranties of any kind, whether express or implied, including but not limited to implied warranties of merchantability, fitness for a particular purpose, and non-infringement. Derstina does not warrant that the Service will meet your requirements, be uninterrupted, timely, secure, or error-free, or that any defects will be corrected.

11. Termination

You may terminate your account at any time by canceling your subscription and contacting us at support@derstina.com.

We reserve the right to suspend or terminate your account at our sole discretion, without prior notice, if we believe that you have violated these Terms or engaged in conduct that is harmful to other users, third parties, or Derstina. Upon termination:

• Your right to access and use the Service will cease immediately
• We may delete your account data after a reasonable retention period
• Provisions of these Terms that by their nature should survive termination will continue to apply, including intellectual property rights, limitation of liability, and dispute resolution

12. Indemnification

You agree to indemnify, defend, and hold harmless Derstina and its officers, directors, employees, and agents from and against any claims, liabilities, damages, losses, and expenses (including reasonable legal fees) arising out of or in connection with your use of the Service, your violation of these Terms, or your infringement of any third-party rights.

13. Changes to These Terms

We may update these Terms from time to time. When we make material changes, we will notify you by email or through a notice on the Service at least 30 days before the changes take effect. Your continued use of the Service after the updated Terms become effective constitutes your acceptance of the changes.

We encourage you to review these Terms periodically. The "Last updated" date at the top of this page indicates when the Terms were last revised.

14. Governing Law and Dispute Resolution

These Terms shall be governed by and construed in accordance with applicable law, without regard to conflict-of-law principles. Any disputes arising out of or relating to these Terms or the Service shall first be attempted to be resolved through good-faith negotiation between the parties.

If a dispute cannot be resolved through negotiation within 30 days, either party may pursue resolution through binding arbitration or in the courts of competent jurisdiction, as permitted by applicable law in your jurisdiction.

15. General Provisions

• Entire Agreement. These Terms, together with our Privacy Policy, constitute the entire agreement between you and Derstina regarding the Service.
• Severability. If any provision of these Terms is found to be unenforceable, the remaining provisions will continue in full force and effect.
• Waiver. Our failure to enforce any right or provision of these Terms shall not constitute a waiver of that right or provision.
• Assignment. You may not assign or transfer your rights under these Terms without our prior written consent. We may assign our rights and obligations without restriction.
• Notices. We may provide notices to you via the email address associated with your account or through the Service.

16. Contact Us

If you have any questions about these Terms of Service, please contact us at:

Email: support@derstina.com
Website: derstina.com