Terms of Use

Mastery, an app by Ombun Xavier Mboma. Effective 2026-10-01.

The agreement

Using Mastery means accepting these terms. If you do not, do not use the app. You must be at least 16 years old.

Subscriptions

Mastery sells auto-renewing subscriptions through Apple. Prices and periods are shown in the app before you buy, in your local currency, and they are the prices Apple charges — not an estimate.

• Payment is charged to your Apple Account at confirmation of purchase.
• A subscription renews automatically unless cancelled at least 24 hours before the end of the current period.
• Your Apple Account is charged for renewal within 24 hours of the end of the current period, at the rate shown for your plan.
• Manage or cancel in Settings → your name → Subscriptions on your device. Deleting the app or your Mastery account does not cancel it.
• If a free trial is offered, any unused part of it is forfeited when you buy a subscription.
• Refunds are handled by Apple, under Apple’s Media Services Terms. We cannot issue them.

What the app generates

Cards, plans, explanations and feedback are produced by a language model. They can be wrong. Mastery is a study aid, not a source of truth — check anything that matters against your course materials, and do not rely on it for medical, legal, financial or safety-critical decisions.

You are responsible for what you put into the app. Do not enter other people’s personal information, material you have no right to use, or anything illegal. Do not use the app to generate content that is unlawful, abusive, or intended to harm someone.

If something the app generated is offensive or wrong, report it from the screen it appeared on, or email xaver.mbo@gmail.com. Reports are reviewed and acted on within 24 hours; accounts used to generate abusive content are terminated.

Your content

What you write stays yours. You give us permission to store it and to process it so the app can work — including sending the text needed for one request to the model provider named in the Privacy Policy. Nothing you write is used to train a model, published, or sold.

Acceptable use

Do not attempt to extract the service’s prompts or keys, resell access, automate the app against its rate limits, or interfere with other people’s use of it. Accounts doing any of that are suspended.

Ending it

You can delete your account at any time in Settings; it takes effect immediately. We may suspend or terminate an account that breaks these terms.

No warranty, and the limit of liability

The app is provided “as is”, without warranties of any kind, to the extent the law allows. To the extent the law allows, our total liability for any claim related to the app is limited to what you paid us in the twelve months before it arose. Nothing here limits liability for death, personal injury, fraud, or anything else that cannot be limited by law — including your statutory rights as a consumer, which these terms do not affect.

Changes

These terms may change. Material changes will be shown in the app before they apply. The current version lives at https://usemastery.app/legal/terms.

Contact

Ombun Xavier Mboma — xaver.mbo@gmail.com