Privacy Policy

Last Updated: October 2026

This Privacy Policy specifically governs the mobile application Hertzia - Frequency Healing ("Hertzia", the "App"), developed and published by Mayone Co., Ltd. ("Company", "we", "us", or "our"), a company registered under the laws of Vietnam.

We are committed to respecting and protecting the privacy of our users. This policy clearly explains our data collection, handling, and security practices in full compliance with the Google Play Developer Program Policies (User Data & Privacy Policy requirements), the General Data Protection Regulation (GDPR), and the California Consumer Privacy Act (CCPA).

1. Information We Collect and How We Use It

Hertzia is designed as an acoustic frequency therapy and meditation tool. We strictly adhere to the principle of data minimization:

• (a) On-Device Local Data (Non-Personal): Your audio preferences, custom sound mixes, favorite Solfeggio tones, playlist selections, and sleep timer configurations are stored purely locally on your device storage (via local Preferences / SQLite database). We do NOT upload or store your personal listening history on external servers.
• (b) Device & Performance Diagnostics: Like most mobile apps, our third-party SDK partners (such as Google Play Services and Firebase) may automatically collect technical, non-personally identifiable diagnostic data including device model, operating system version, crash reports, ANR logs, language preferences, and aggregated session durations to monitor app stability and performance.
• (c) Transaction & Purchase Data: If you purchase a premium subscription or lifetime VIP unlock, all payment transactions are handled directly and securely through the official Google Play In-App Billing system. We do NOT access, process, or store your credit card, debit card, or payment credentials.

2. Device Permissions and Why We Request Them

To deliver a smooth acoustic healing experience, Hertzia requests the following standard Android permissions:

• FOREGROUND_SERVICE & FOREGROUND_SERVICE_MEDIA_PLAYBACK: Required to keep relaxing soundscapes, Solfeggio tones, and sleep frequencies playing continuously without stuttering when your device screen is locked or when running in the background.
• WAKE_LOCK: Prevents the device CPU from sleeping during active guided meditation or overnight sleep playback.
• INTERNET & ACCESS_NETWORK_STATE: Allows the application to stream audio assets from our content delivery network (CDN) and communicate with Google Play to verify subscription entitlements.
• BILLING (com.android.vending.BILLING): Enables in-app purchase of Hertzia VIP subscription plans via Google Play.

Note: Hertzia does NOT request or access sensitive device permissions such as precise GPS location, microphone audio recording, phone camera, contacts, or SMS.

3. Third-Party Services and Data Sharing

We do not sell, rent, or trade your personal data. We only partner with reputable third-party service providers that adhere strictly to industry privacy standards:

• Google Play Services & In-App Billing: Provides app distribution, security verification, and secure in-app payments. (Google Privacy Policy)
• Firebase Analytics & Crashlytics (by Google): Analyzes aggregated crash statistics to help us diagnose bugs and improve app stability.
• Google AdMob / Advertising Partners (if applicable on free tiers): May utilize the resettable Google Advertising ID (GAID) to display contextual or non-personalized advertisements according to Google Play Policies. You can reset or delete your GAID at any time in your Android device settings under Settings > Google > Ads.

4. Children’s Privacy (COPPA & GDPR-K)

Hertzia is intended for a general audience (aged 13 and older, and 18+ for paid subscriptions). We do not knowingly collect, solicit, or maintain personal information from children under the age of 13. If we discover that a child under 13 has provided personal information to us, we will promptly delete it. If you believe your child has submitted personal data, please contact us immediately at mayoneltd2026@gmail.com.

5. Data Retention, Security & User Deletion Rights

We implement industry-standard physical and electronic safeguards to protect any diagnostic data collected. Because user settings and preferences are stored locally on your device, you can delete all app data at any time by clearing the app data in your device's App Settings or by uninstalling the App.

If you have contacted our customer support via email and wish to request the deletion of your correspondence or any associated records, please email us with your request at mayoneltd2026@gmail.com or npngocanh228@gmail.com, and we will fulfill your request within 30 days.

6. Changes to This Privacy Policy

We may periodically update this Privacy Policy to reflect app enhancements or legal requirements. Any modifications will be posted directly to this URL with an updated "Last Updated" timestamp. We encourage you to review this page periodically.

7. Contact Information & Legal Entity

If you have any questions, inquiries, or feedback regarding this Privacy Policy or Hertzia's data practices, please contact us:

• 🏢 Entity Name: Mayone Co., Ltd.
• 📱 Application: Hertzia - Frequency Healing
• 📧 Primary Contact: mayoneltd2026@gmail.com
• 📧 Support Email: npngocanh228@gmail.com
• 🌐 Official Website: https://mayone.vercel.app