Privacy policy

1. Who we are

This policy covers the Chinese Tone Trainer mobile apps for Android and iOS, published by Merry Mandarin. The company responsible for the product and for personal information we receive is:

2. Microphone access and recordings

When you choose to record, the app requests Android’s RECORD_AUDIO permission or the corresponding iOS microphone permission. If you allow it, the app captures your voice to calculate pitch, display your tone contour, provide practice feedback, and replay the current take. Nearby voices and sounds may also be captured while recording.

Audio is analyzed locally. It is not uploaded to us or to any third party, used to train a model, or used to identify you. The app does not record in the background; recording stops when the app leaves the foreground.

The current take is held in memory. On iOS, replay can also use a temporary app-private audio file. The app attempts to remove that file when changing the take, leaving the foreground, closing normally, and starting again. If the app is interrupted, a temporary file may remain until cleanup on a later launch or removal of app data. Practice history is not an archive of your audio recordings.

You can decline microphone access or revoke it in your device settings at any time. Recording and pitch feedback will then be unavailable. Dictionary browsing, reference playback, and other features that do not require a microphone can still be used.

3. Data stored on your device

The voice and dictionary are included with the installed app. Practice does not require a model download, sign-in, or an internet connection. We do not receive a copy of your local practice data.

Your operating system may offer its own device diagnostics, backups, or transfers. Android app backup is disabled in the app configuration. Any backup or transfer performed by a device platform is subject to that platform’s settings and policies.

4. Retention and deletion

• Current recording: replaced when you start another take or change practice material. Memory is released when the app process ends. Temporary replay files are handled as explained in section 2.
• Practice history: retained locally until you remove it. Choose Settings → Clear practice history to remove saved rounds and pitch traces. Saved sentences remain.
• Saved sentences: remove a sentence from the saved sentence list. Its earlier practice rounds remain until you clear practice history.
• Preferences and reference audio: remain in app-private storage until replaced, evicted from the size-limited voice cache, or cleared with app data.
• All app data: clear the app’s storage or delete the app through your device settings. Offloading an app or keeping its data is different from deleting its data. Manage any device backup copies separately.

There is no account to delete. Because we do not hold your local data, we cannot recover deleted practice history or erase it remotely.

5. Support and app stores

If you email us, we receive your email address, message, and any attachments you choose to send. We use them to respond and resolve your request. Only send a recording or other personal information if you want our support team to receive it. Our email provider processes correspondence to deliver and store those messages.

We keep support correspondence for as long as needed to address your request, resolve follow-up issues, and meet applicable recordkeeping or legal requirements. You can request deletion of information we no longer need.

Google Play and the Apple App Store process downloads and store transactions under their own policies. We do not receive your payment-card details. The store may make order information available to us for purchase support. The app version covered by this policy has no account or purchase-tracking SDK.

See Google’s privacy policy and Apple’s privacy policy for their handling of store information.

6. Security and sharing

The app relies on operating-system app storage protections and permission controls. We do not claim separate end-to-end encryption of local preferences or pitch traces. Your device’s screen lock, security settings, and operating-system protections also help protect your data.

We do not sell personal information, share it for targeted advertising, or transmit local practice data to other parties. Information you deliberately send to support is handled by the people and providers needed to respond. We may disclose information we hold where legally required or necessary to establish, exercise, or defend a legal claim.

We are based in Taiwan. Support correspondence may be processed there and in countries where our email provider operates. Where applicable law requires safeguards for international transfers, we use the relevant contractual protections. Contact us for information about safeguards relevant to your request. These support arrangements do not transfer your locally stored app data.

7. Legal grounds and your rights

Microphone access is optional and requires your affirmative permission. Local processing provides the practice features you request. You can withdraw microphone permission in device settings without affecting processing already performed.

Where the EU or UK GDPR applies to information we receive, we rely on providing a requested service (Article 6(1)(b)) for product and purchase support; legitimate interests (Article 6(1)(f)) for answering general correspondence and resolving issues; and legal obligations (Article 6(1)(c)) for required records or disclosures. Where consent is required for an optional use, we obtain it separately. Microphone permission is not permission for marketing or uploading audio.

Depending on applicable law, you may request access to, copies of, correction of, or deletion of personal information; object to or restrict processing; withdraw consent; or exercise data-portability rights. Your rights under Taiwan’s Personal Data Protection Act and other applicable privacy laws are not waived.

Use the app and device controls for data held only on your device. For information we hold, contact [email protected]. We may need proportionate information to verify a request and will respond within the period required by law. You may complain to your competent data-protection authority.

Practice scores are educational feedback. They are not automated decisions with legal or similarly significant effects.

8. Children

The app is intended for learners aged 13 and older. Learners who cannot legally agree to the terms themselves should use it with a parent or guardian’s permission and supervision. We do not knowingly collect children’s personal information through the app. If a child sends information to support, a parent or guardian may contact us to request its removal.

9. Policy updates

We will revise this policy and its date if the app’s data practices change. Material changes will be communicated through an appropriate notice, and consent will be requested where required. Updating the policy does not itself grant consent for a new use of your data.

For questions, contact the company in section 1. This policy does not limit your statutory rights.