Privacy Policy

1. Introduction

Welcome to SayNiHao, a Chinese language learning application developed by Kai Yuan Su ("I", "me", or "Developer"). This Privacy Policy explains how I collect, use, disclose, and safeguard your information when you use the App.

By using SayNiHao, you agree to the collection and use of information in accordance with this policy. If you do not agree, please do not use the App.

2. Information I Collect

Information You Provide

• Account information: name, email address, and profile photo (when you sign in with Google or Apple).
• Learning preferences: your native language, target HSK level, and daily learning goals.
• User-generated content: sentences you write, pronunciation recordings made during practice sessions, flashcard content you create, and essay/translation responses written during HSK mock exams.
• Feedback and communications: messages you send through the in-app contact form.

Information Collected Automatically

• Device information: device type, operating system version, and app version.
• Usage data: lessons completed, XP earned, streaks, quiz results, and learning progress.
• Exam data: mock exam results including your answers, section scores, AI-generated essay feedback, completion time, and timestamps.
• Advertising identifiers: used to serve relevant advertisements (non-premium users only).

3. How I Use Your Information

• Provide, maintain, and improve the App and its features.
• Personalize your learning experience based on your level and preferences.
• Process your essay and translation responses through secure Cloud Functions for AI-powered grading (mock exams). Your responses are sent to Anthropic Claude API server-side; the AI returns a score and feedback that is stored in your private exam results.
• Analyze your pronunciation recordings by sending the audio to Google Gemini and/or OpenAI (Whisper) for transcription and tone scoring; the audio is processed transiently and is not stored on our servers.
• Process in-app purchases and subscriptions via RevenueCat.
• Send you weekly learning reports and study reminders (only if you enable notifications).
• Display relevant advertisements to non-premium users via Google AdMob.
• Analyze usage trends to improve the App.
• Respond to your feedback and support requests.
• Comply with legal obligations.

4. Third-Party Services

SayNiHao uses the following third-party services, each governed by their own privacy policies:

• Firebase Authentication, Firestore, Storage, and Cloud Functions (Google) — authentication, database, file storage (exam illustration images), and server-side AI grading.
• Google AdMob — advertising for non-premium users.
• RevenueCat — subscription and in-app purchase management.
• Anthropic Claude API — AI-powered conversation practice, sentence grading, and essay grading for HSK mock exams. Essay responses are processed via secure server-side Cloud Functions.
• Google Gemini API — pronunciation tone analysis (your voice recordings are sent for scoring).
• OpenAI API — speech transcription (Whisper) of your pronunciation recordings as a fallback scoring layer, and text-to-speech generation of lesson and exam audio.
• Google Speech-to-Text — on-device voice recognition during chat and sentence practice.
• Resend — delivery of transactional emails (such as account verification and password-reset emails); your email address is shared for this purpose.

5. Data Storage and Security

Your data is stored securely on Google Firebase servers. I implement commercially reasonable security measures including Firestore Security Rules to ensure that only you can read or modify your personal data. However, no method of transmission over the Internet or electronic storage is 100% secure.

Voice recordings made during pronunciation practice are sent to third-party AI services (Google Gemini and OpenAI Whisper) for transcription and tone scoring. The audio is processed transiently for this purpose and is not permanently stored on our servers; its handling by those providers is governed by their respective privacy policies.

Exam results, including your essay responses and AI-generated feedback, are stored in your private examResults collection in Firestore. These records are accessible only to you and are subject to your account deletion requests. Cloud Functions process essay grading server-side; the Anthropic API key is stored in Google Secret Manager and never exposed to the client.

Exam illustration images (educational line drawings) are downloaded from Firebase Storage and are static, publicly readable content. No user-generated images are uploaded.

6. Children's Privacy

7. Your Rights and Choices

You have the following rights regarding your personal data:

• Access: View your personal information through the Profile screen, including learning progress, achievements, exam history, and account details.
• Correction: Update your account information (name, native language, learning goals) anytime in Profile settings.
• Deletion: Permanently delete your account and all associated data using the "Delete Account" feature in Profile. This action erases your learning progress, achievements, flashcards, exam results (including essay responses and AI feedback), and account information from our systems.
• Portability: Request a copy of your personal data by emailing book8692978@gmail.com.
• Opt-out: Opt out of personalized advertising by upgrading to a premium subscription, or disable notifications anytime through device settings.
• Withdraw consent: Stop using the app at any time. To prevent further data collection, delete the app and request account deletion.

For users in the European Economic Area (GDPR): You have additional rights including the right to lodge a complaint with your local data protection authority. The legal basis for processing is your consent (for optional features like notifications and personalized ads) and contract performance (for core learning features).

For California residents (CCPA): I do not sell your personal information. You have the right to know what information is collected and to request deletion as described above.

8. Data Retention

I retain your data for as long as your account is active. This includes learning progress, achievements, flashcards, and exam results with associated essay responses and AI-generated feedback. When you delete your account, all associated personal data is permanently deleted from our systems, typically within 30 days. Anonymized usage statistics may be retained for analytics purposes.

9. International Users

SayNiHao is operated from Taiwan. If you access the App from outside Taiwan, your information may be transferred to and processed in Taiwan and on servers located in the United States (via Google Firebase). By using the App, you consent to such transfer.

10. Changes to This Policy

I may update this Privacy Policy from time to time. I will notify you of any changes by updating the "Effective Date" at the top of this policy. Continued use of the App after changes constitutes your acceptance of the updated policy.