Language of the Agreement: These Terms of Service are originally written in English. We may provide translations for convenience. In the event of any conflict between the English version and any translation, the English version shall strictly prevail.
These Terms of Service ("Terms") constitute a binding legal agreement governing your use of the websites at yifolio.com and vocabfolio.app (collectively, the "Websites"), the VocabFolio Android mobile application available on the Google Play Store, and all services offered through them (collectively, the "Service"). By accessing or using the Service, you confirm you have read, understood, and agree to be bound by these Terms.
If you do not agree to these Terms, you must not access or use the Service.
The owner of the Websites and the party responsible for the Service is:
The Service is strictly not intended for anyone under the age of 13. By creating an account, you declare that you are at least 13 years old. If you believe a child under 13 has registered, please notify us immediately at contact@vocabfolio.app or hello@yifolio.com so we can delete the account and all associated data without delay.
If you are a teacher, school official, or administrator using the Service on behalf of students:
Students who join a Class created by a teacher acknowledge that their learning activity data (quiz scores, answer history, study session data) may be visible to their teacher within the VocabFolio platform.
You may register using your email address or through a supported third-party authentication provider (Google, Microsoft, Facebook, or Apple). You are responsible for maintaining the confidentiality of your account credentials and for all activity that occurs under your account. Notify us immediately at contact@vocabfolio.app or hello@yifolio.com if you suspect unauthorized access.
During registration and onboarding, we may collect your full name, username, native language, and role (student or teacher). Age and gender are optional fields — you are not required to provide them to register or use the Service. This information is used to personalize your learning experience and is handled in accordance with our Privacy Policy.
The Websites may contain links to third-party websites or services not owned or controlled by Yi Folio LLC.
VocabFolio is available in three tiers:
Yi Folio LLC may offer time-limited free trials of Advanced or Premium features. Trial terms (duration and eligible features) are communicated at the time of offer. Only one trial per feature set is permitted per user account.
VocabFolio operates a referral program. When you share your unique referral code and a new user signs up using it, you may earn bonus days or months of Advanced or Premium access, subject to the limits communicated in the application. Bonus access is a temporary extension of your account's features and does not constitute a paid subscription. Yi Folio LLC reserves the right to modify or discontinue the referral program at any time.
All payments for Advanced and Premium subscriptions are processed by our third-party payment gateway, Stripe. By upgrading, you agree to Stripe's Terms of Service and Privacy Policy. Yi Folio LLC does not store your full payment card details.
Paid subscriptions renew automatically at the start of each billing cycle (monthly or annual) unless cancelled before the renewal date.
You can view billing history, update payment methods, or cancel your subscription at any time through Settings → Billing in the application, which connects to the Stripe Customer Portal.
If you cancel a paid subscription, it remains active until the end of the current paid period. At that date, your account automatically downgrades to the Free plan. Word categories beyond the Free plan limit will be marked inactive but not deleted; they are restored if you resubscribe.
Yi Folio LLC reserves the right to modify pricing. For active recurring subscriptions, any price increase takes effect at the next billing cycle, with at least 15 days' prior notice via email to your registered address.
Due to the nature of digital services, access to Advanced or Premium features begins immediately upon subscription activation. By accessing paid content, you acknowledge that you waive your automatic right of withdrawal or cooling-off period, to the extent permitted by law.
Refunds are not provided for partial billing periods or for trial conversions, except where required by applicable consumer protection law in your jurisdiction. If you believe you are entitled to a refund under local law, please contact contact@vocabfolio.app or hello@yifolio.com within 14 days of the charge.
You retain ownership of vocabulary lists, custom notes, categories, and other content you create ("User Content"). By submitting User Content, you grant Yi Folio LLC a worldwide, royalty-free license to store, display, and process your content solely for the purpose of providing the Service to you.
VocabFolio includes a list-sharing feature (available on Advanced and Premium plans) that allows you to share a chosen vocabulary list from your word bank with others via a link.
Share Link. When you click "Share Link," the app generates a unique URL containing a random share token (not your database record ID, to prevent guessing or enumeration). You may distribute this link through any channel you choose (e.g., WhatsApp, email, social media). Anyone who receives and opens this link can view the shared vocabulary list — including people who do not have a VocabFolio account (guest access). The list remains accessible via the link until you delete the shared list.
Send Email. When you click "Send Email," you may enter recipient email addresses. These addresses are used solely to dispatch the sharing email containing the link. Recipient email addresses are not stored in your shared list record or retained by Yi Folio LLC after the email is sent. The link included in the email is identical to the "Share Link" above and grants the same guest-accessible viewing.
What Shared List Viewers Can See. Anyone opening a shared list link (with or without an account) can view: the list title, vocabulary words, and associated details you have included. They cannot edit the list, access your account, or see any other content from your word bank.
Your Responsibility. Because any holder of the link can view the shared list, you should not include sensitive, confidential, or personally identifiable information in any vocabulary list you intend to share. You can revoke access at any time by deleting the shared list.
You agree NOT to post, upload, or share content that is illegal, defamatory, obscene, pornographic, harassing, hate speech, or that promotes violence or discrimination. Yi Folio LLC reserves the right to remove any User Content and suspend or terminate any account that violates these standards, without prior notice.
All intellectual property rights in the Websites, application functionality, original branding, design, and teaching materials are the exclusive property of Yi Folio LLC. You must not:
AI-generated definitions, translations, and quiz content are generated for your personal learning use. You may not resell, republish, or commercialize AI-generated content produced by the Service.
VocabFolio uses artificial intelligence (AI) to generate English definitions, native language translations, example sentences, quiz questions, and customer support responses. While we strive for accuracy, AI systems may occasionally produce incorrect, incomplete, or contextually inaccurate output (commonly referred to as "hallucinations").
AI-generated definitions, translations, and quiz materials are for general learning purposes only and should not be relied upon for academic, legal, or professional translation accuracy.
Responses from the AI customer support assistant do not constitute a legally binding statement or warranty on behalf of Yi Folio LLC. If the AI cannot resolve your issue, your query is escalated to a human support representative via a Support Ticket.
VocabFolio is available as:
Certain features may differ between the web and mobile versions of the Service. We will communicate material feature differences in the application or via email.
You may close your account at any time through:
Both paths are available to Android app users in compliance with Google Play's account deletion requirements. In-app deletion takes effect immediately; web/email requests are completed within 30 days of identity verification, except where we are legally required to retain certain records (e.g., billing records for tax purposes).
Yi Folio LLC reserves the right to suspend or permanently terminate your account, with or without advance notice, if we determine that you have:
Where reasonably practicable, we will provide advance notice and an opportunity to address the issue. Upon termination, your access to paid features ceases immediately. Prepaid fees for unused periods are not refundable unless required by applicable law.
You agree to indemnify, defend, and hold harmless Yi Folio LLC, its officers, directors, employees, and agents from and against any claims, damages, losses, liabilities, costs, and expenses (including reasonable legal fees) arising out of or related to: (a) your use of the Service; (b) your User Content; (c) your violation of these Terms; (d) your violation of any rights of a third party; or (e) any student data you upload or submit in connection with a class.
THE SERVICE IS PROVIDED ON AN "AS IS" AND "AS AVAILABLE" BASIS WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, YI FOLIO LLC SHALL NOT BE LIABLE FOR: (A) ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES; (B) LOSS OF PROFITS, DATA, OR GOODWILL; (C) SERVICE INTERRUPTIONS DUE TO INTERNET ISSUES, FORCE MAJEURE, OR THIRD-PARTY PROVIDER OUTAGES; OR (D) ERRORS IN AI-GENERATED CONTENT.
If you believe that content on the Service infringes your copyright, please send a written notice to contact@vocabfolio.app or hello@yifolio.com including: (1) identification of the copyrighted work claimed infringed; (2) identification of the infringing material and its location on our Service; (3) your contact information; (4) a good faith belief statement; and (5) a statement under penalty of perjury that the information is accurate and you are authorized to act. We will respond to valid notices in accordance with applicable law.
For non-material changes (e.g., clarifications), we will update the "Last Updated" date and the change takes effect immediately. For material changes (e.g., payment terms, user rights), we will notify you via email to your registered address at least 15 days before the changes take effect. Your continued use of the Service after the effective date constitutes acceptance of the updated Terms.
These Terms shall be governed by and construed in accordance with the laws of the State of Wyoming, United States, without regard to its conflict of law provisions. For EU or Taiwan users, mandatory consumer protection laws of your country of residence also apply and are not overridden by this clause.
Disputes shall first be attempted through good-faith negotiation. If not resolved within 30 days, disputes shall be submitted to the exclusive jurisdiction of state or federal courts in Wyoming, USA, unless applicable consumer protection law in your jurisdiction requires otherwise.
This section applies specifically to your use of VocabFolio via the Android app available on the Google Play Store.
The VocabFolio Android app is distributed through the Google Play Store. As a condition of using the Android app, you agree to comply with Google Play's Terms of Service. In the event of a conflict between these Terms and Google Play's Terms of Service, Google Play's Terms shall prevail for matters relating to the distribution and download of the app from Google Play.
VocabFolio subscriptions on Android are currently processed through Stripe via the in-app web checkout. If in-app purchases through Google Play Billing are introduced in the future, the following will apply:
As required by Google Play's User Data Policy, Android users may delete their VocabFolio account through any of the methods described in Section 13.1. Deleting your account removes your personal data, as described in Section 13 and in our Privacy Policy.
The VocabFolio Android app may request the following device permissions, which you may grant or deny:
No permission is required for the app's core vocabulary learning functionality.