Privacy Policy

Last Updated: January 2025

1. Overview

Welcome to Tone Master! We take your privacy and personal data protection seriously. This privacy policy explains how we collect, use, store, and protect your information when using the Tone Master app.

2. Information Collection

2.1 Information We Collect

Tone Master is an app focused on offline learning. The information we collect and store includes:

  • Learning Progress Data - Including completed lessons, practice records, answer accuracy rates, and other learning-related data
  • Error Records - List of characters you answered incorrectly during practice, used to generate personalized review content
  • Favorite Content - List of characters and phrases you've favorited
  • App Settings - Including audio volume, playback speed, auto-play preferences, and other settings
  • Learning Statistics - Learning days, consecutive check-in days, mastered character count, and other statistics

2.2 Audio Recordings

When you use the tone recognition and pronunciation practice features, Tone Master may record your voice through your device's microphone. These audio recordings are:

  • Used for Real-Time Analysis - Your audio recordings are processed by third-party audio analysis services (Xunfei) to provide pronunciation feedback and tone recognition
  • Temporarily Processed - Audio data is transmitted to Xunfei's cloud services for analysis and is not permanently stored by us
  • Not Saved Locally - Your audio recordings are not saved to your device unless you explicitly choose to save them

2.3 Information We Do NOT Collect

To protect your privacy, Tone Master does NOT collect the following information:

  • Personal identification information (name, phone number, email address, etc.)
  • Device location information
  • Contact lists
  • Camera data
  • Any other personal information unrelated to learning

3. How We Use Your Information

The information we collect is used only for the following purposes:

  • Provide Core Features - Save your learning progress and provide a personalized learning experience
  • Generate Review Content - Intelligently generate review lists based on your error records
  • Statistics and Learning Data - Display your learning progress, achievements, and statistics
  • Improve User Experience - Provide a better learning experience based on your settings preferences
  • Audio Analysis - Process your audio recordings through Xunfei's audio analysis services to provide real-time pronunciation feedback and tone recognition

We do NOT use your information for any marketing purposes, and we do NOT share, sell, or exchange your personal data with third parties except as necessary to provide the audio analysis services described in this policy.

4. Data Storage

4.1 Local Storage

Tone Master uses local storage for all user learning data. All your learning data, progress, settings, and favorite content are stored in your device's local SQLite database and are not uploaded to any remote server.

Note: While some audio files may be downloaded from Firebase Storage to your device's local cache, this does not involve uploading any of your personal data or learning information. The download process is one-way only - from the cloud to your device, never from your device to the cloud.

This means:

  • You have complete control over your learning data
  • Most features work without internet connection (except audio analysis features)
  • Your learning data (progress, errors, favorites) is not accessible by us or any third party
  • Uninstalling the app will delete all locally stored data

4.2 Audio Data Processing

Important Exception: When you use tone recognition or pronunciation practice features, your audio recordings are temporarily transmitted to Xunfei's cloud services for analysis. This is necessary to provide real-time pronunciation feedback. The audio data is processed by Xunfei and is not permanently stored by us. However, Xunfei may process and store your audio data according to their own privacy policy.

5. Audio Content and Analysis

5.1 Audio Files

Audio files (character and phrase pronunciations) in the Tone Master app are provided through two methods:

  • Local Audio Files: Most audio files are packaged within the app and stored locally on your device.
  • Firebase Storage: Some audio files may be downloaded from Firebase Storage (a cloud storage service provided by Google) to your device's local cache when needed. These downloads are one-way only - we download audio files to your device, but we do not upload any of your personal data or learning information to Firebase Storage.

All downloaded audio files are cached locally on your device for offline use. These audio files are used solely for educational learning purposes and do not involve any personal data. You can clear the audio cache at any time through the app settings.

5.2 Audio Analysis Services

When you use the tone recognition and pronunciation practice features, your audio recordings are processed by Xunfei (讯飞) audio analysis services to provide:

  • Speech Recognition (ASR) - Converting your speech to text for free recognition features
  • Pronunciation Evaluation (ISE) - Analyzing your pronunciation accuracy, tone recognition, and providing detailed feedback

Important: Your audio recordings are transmitted securely to Xunfei's cloud services for real-time analysis. The audio data is processed to provide pronunciation feedback and is not permanently stored by us. However, Xunfei may process and temporarily store your audio data according to their own privacy policy. We recommend reviewing Xunfei's privacy policy for more information about how they handle audio data.

You can control microphone access through your device settings. If you disable microphone permissions, tone recognition and pronunciation practice features will not be available.

6. Third-Party Services

Tone Master uses the following third-party services:

  • Firebase Storage (Google): We use Firebase Storage solely to provide audio file downloads. When you use the app, some audio files may be downloaded from Firebase Storage to your device's local cache. Important: This is a one-way process - we only download audio files to your device. We do not upload, transmit, or share any of your personal data, learning progress, error records, favorites, or any other user information to Firebase Storage.
  • Xunfei (讯飞) Audio Analysis Services: We use Xunfei's cloud-based audio analysis services for speech recognition and pronunciation evaluation. When you use tone recognition or pronunciation practice features, your audio recordings are transmitted to Xunfei's servers for real-time analysis. This service is essential for providing pronunciation feedback and tone recognition. Your audio data is processed according to Xunfei's privacy policy and terms of service. We do not control how Xunfei processes or stores your audio data, but we ensure that only audio recordings necessary for analysis are transmitted, and no other personal data or learning information is shared with Xunfei.

Tone Master does not use any third-party analytics services, advertising services, or user data collection tools. Your learning data (progress, error records, favorites, settings) remains completely private and local to your device and is never shared with any third-party service.

7. Children's Privacy

Tone Master is suitable for users of all ages. Since we do not collect any personal identification information and do not require user registration, children can safely use this app.

We recommend that parents and guardians supervise children's use of mobile applications.

8. Data Security

Although your data is completely stored on your local device, we still take data security seriously:

  • Use secure local database (SQLite) for data storage
  • Follow mobile platform security best practices
  • Regularly update the app to fix potential security issues

Please note that you are responsible for protecting your device security, including setting device passwords, keeping the operating system updated, etc.

9. Your Rights

Since all data is stored locally on your device, you have complete data control:

  • Right to Access - You can view all learning data and statistics in the app at any time
  • Right to Modify - You can modify your preferences and configurations through app settings
  • Right to Delete - You can clear error records, delete favorites in the app, or delete all data by uninstalling the app
  • Right to Export - Your data is stored in a local database, and technical users can export it through device backups

10. Changes to Privacy Policy

We may update this privacy policy from time to time. If there are significant changes, we will notify you through in-app notifications or app store update descriptions. Continued use of the app indicates your acceptance of the updated privacy policy.

We recommend that you review this privacy policy regularly to understand how we protect your information.

11. Contact Us

If you have any questions, comments, or suggestions about this privacy policy, or wish to exercise your data rights, please contact us through the following:

Email: lij110397@163.com

We will respond to your email within 24 hours.

12. Applicable Law

This privacy policy is governed by the laws of the People's Republic of China. We are committed to complying with all applicable data protection laws and regulations.

Summary

Tone Master's Privacy Commitment:

  • ✅ All learning data (progress, errors, favorites, settings) is completely stored locally and not uploaded to any server
  • ✅ No personal identification information is collected
  • ✅ Firebase Storage is used only for downloading audio files (one-way process)
  • ✅ Xunfei audio analysis services are used only for real-time pronunciation feedback and tone recognition
  • ✅ Audio recordings are processed by Xunfei but not permanently stored by us
  • ✅ No third-party analytics or advertising services are used
  • ✅ Your learning data is not shared with any third parties
  • ✅ You have complete control over your learning data
  • ✅ Most features support offline use (audio analysis features require internet connection)

Our goal is to provide a secure, private, and learning-focused environment where you can confidently use Tone Master to learn Chinese tones. We use audio analysis services only when necessary to provide pronunciation feedback, and we ensure that your learning data remains private and local to your device.