Terms of Service
Effective October 25, 2026 · Version 1.1
This is an English translation of the Korean original. If the two differ, the Korean version prevails.
These terms set out the conditions and procedures for using mellow (the “Service”) and the rights and obligations of users and the operator.
Article 1 (What the Service is)
The Service is a mobile application for practicing foreign-language conversation through real-time voice calls with AI characters. After a call ends, it provides grammar corrections, a report and review items based on the conversation.
The conversation partner is an AI model, not a person. Sentences, pronunciation guidance and corrections generated by the Service may be inaccurate, and are not suitable as a basis for purposes where accuracy matters, such as exams, qualifications or work.
Article 2 (Sign-up and accounts)
- Users can sign up with an email address or a Kakao, Google or Apple account. Only people aged 14 or older may use the Service.
- An account may be used only by its owner and may not be transferred or lent to others.
- Users can delete their account in the app at any time. Deleting an account also deletes call records and learning records, and they cannot be recovered.
Article 3 (Free use and subscriptions)
The Service can be used for free, and free users can make calls twice a week, up to 5 minutes per call. Usage resets every Monday.
Subscribing removes the limit on the number of calls, and each call can last up to 60 minutes. Subscription products and prices are shown on the subscription screen in the app, and the amount actually charged is the amount shown in the App Store or Google Play.
Article 4 (Payment and renewal)
- Payment is made through the Apple App Store or Google Play, and the Service does not receive payment method information.
- Subscriptions renew automatically. Unless canceled at least 24 hours before the end of the current subscription period, the subscription renews on the same terms, and the renewal fee is charged at that time.
- Subscriptions can be canceled in the App Store or Google Play subscription settings on the device. After canceling, paid features remain available until the end of the period already paid for.
Article 5 (Refunds)
Refunds of subscription payments follow the refund policies and procedures of Apple or Google, whichever processed the payment. The Service operator cannot issue refunds directly without going through the store, so refunds must be requested from that store.
If there was a period during which the Service could not be used due to the operator’s fault, users may request corresponding compensation as provided by applicable laws.
Article 6 (User obligations)
Users must not do any of the following.
- Misappropriating another person’s account or personal information
- Reverse engineering the Service, making mass calls to it by automated means, or circumventing usage limits
- Entering illegal content or content that infringes others’ rights during calls
- Interfering with the normal operation of the Service
Article 7 (Rights to content)
Rights to what users say during calls belong to the users. The operator uses it only to the extent necessary to provide the Service (running calls, generating reports, generating review items).
Rights to the characters, screens, logos and software provided by the Service belong to the operator, and users may use them only for personal learning purposes.
Article 8 (Suspension and changes to the Service)
The operator may change or discontinue the content of the Service. Changes unfavorable to paid features are announced in the app and on this page 30 days before they take effect. The Service may be temporarily suspended for unavoidable reasons such as maintenance, outages or natural disasters, in which case advance notice is given where possible.
Article 9 (Limitation of liability)
The operator is not responsible for the results of decisions users make in reliance on the Service’s learning content. However, the operator is liable under applicable laws for damage caused by its intentional misconduct or gross negligence.
Article 10 (Changes to these terms)
When these terms change, notice is given on this page and in the app 7 days before the effective date, or 30 days before for changes unfavorable to users. Users who do not agree to the changed terms may delete their account.
Article 11 (Governing law and jurisdiction)
These terms are governed by the laws of the Republic of Korea, and disputes relating to the use of the Service shall be brought before the court having jurisdiction under the Civil Procedure Act (민사소송법).