Terms of Service

Last updated: 24 July 2026

Welcome to DuōMiàn 多面 ("the App"), a Chinese vocabulary learning product operated by Álvaro García Barbón. By using the App you agree to these terms.

1. Description

DuōMiàn helps you study Mandarin Chinese (HSK 1–3) with spaced repetition, drills, graded reading, and optional AI-assisted practice. Some features are free; others require a Pro subscription, an active free trial, or a license grant (including company-provided seats).

2. Accounts

You may use the App as a guest or sign in with Google. Signing in enables cloud sync, trials, paid entitlements, and AI features that require an account. You are responsible for the security of your Google account and for activity under it.

3. Free tier, trial, and Pro

• Free — core study for HSK 1 and related free features, without payment.
• Free trial — new signed-in accounts may receive a time-limited trial of Pro features (currently 7 days). No card is required for the trial itself.
• Pro — unlocks paid features such as Tea House, Sentence Bloom, and higher HSK content, as shown in the App at the time of purchase or grant.
• Company / gift licenses — Pro access may be granted to specific email addresses by us or by an organization that purchased seats. Access ends when the grant expires or is revoked.

Displayed prices may be charged via Ko-fi membership (manual unlock after payment) or Stripe Checkout when that path is enabled. Taxes and final amounts are those shown at checkout by the payment provider.

4. Payments, cancellations, refunds

• Ko-fi memberships — billed and cancelled under Ko-fi’s terms. After you subscribe with the same email you use in the App, we unlock Pro (typically within 24 hours). Contact hello@alvaroga.com if unlock is delayed.
• Stripe subscriptions (when enabled) — managed in the in-app customer portal or via Stripe receipts. Cancel at period end to stop renewal.
• Refunds — where required by law (including EU consumer rights for digital content where applicable). Otherwise, refunds are at our discretion; email us with your account email and payment reference.

5. Acceptable use

You agree to use the App for lawful educational purposes. You may not:

• Abuse, scrape, or overload APIs or AI features
• Share account credentials to evade seat or subscription limits
• Attempt to reverse-engineer, exploit, or disrupt the App
• Submit illegal, abusive, or harassing content via feedback or AI chat
• Resell access without our written agreement

We may suspend or terminate access for abuse, non-payment, or breach of these terms.

6. AI features

Optional AI features send the content you provide (and limited context needed for the feature) to third-party model providers to generate responses or speech. Outputs may be imperfect; do not rely on them as professional translation or exam authority. See the Privacy Policy for processors.

7. Intellectual property

The App’s software, design, content pipelines, and original materials are owned by the developer. HSK word lists follow publicly available educational standards. You keep ownership of feedback you submit; you grant us a license to use it to improve the App.

8. Availability

We aim for reliable service but do not guarantee uninterrupted uptime. Features may change. We may modify or discontinue parts of the App with reasonable notice where practicable.

9. Privacy

Use of the App is also governed by our Privacy Policy. You can clear progress or delete your account from Settings when signed in, or email us.

10. Disclaimer

The App is provided “as is” without warranties of any kind to the fullest extent permitted by law. We do not guarantee specific learning outcomes or exam results.

11. Limitation of liability

To the maximum extent permitted by law, we are not liable for indirect, incidental, or consequential damages arising from use of the App. Nothing in these terms limits liability that cannot be limited under applicable law (including mandatory consumer protections).

12. Changes

We may update these terms. The date at the top will change. Continued use after material changes constitutes acceptance, except where applicable law requires another process.

13. Contact

Questions: hello@alvaroga.com