Privacy Policy
Last Updated: October 13, 2026
This Privacy Policy describes how [ TwilightSirius ] ("we," "us," or "our"), operating as an individual developer in Taiwan, collects, uses, and discloses your information when you use our mobile application, Heart Rate Monitor & HRV [BLE] (the "Application").
We are committed to protecting your privacy. Please read this Privacy Policy carefully to understand our practices regarding your data.
1. Data Collection and Usage
Health & Measurement Results (Processed Locally Only)
Your personal health metrics, including raw sensor data, calculated Heart Rate (HR), and Heart Rate Variability (HRV) values measured via BLE devices or camera sensors, are processed solely locally on your device for real-time visualization and personal tracking. We do NOT collect, store, or transmit your actual health measurement results to our servers or to any third-party service.
Your Choices at a Glance
Usage statistics: Optional. You can turn them on or off at any time in the Application's Settings. Depending on your region, usage statistics may be off by default until you choose to turn them on. If you decline advertising consent in a consent message shown to you (for example, in the European Economic Area or the United Kingdom), the Application will also turn usage statistics off automatically. You can turn them back on manually in Settings.
Advertising: Your advertising consent choices are managed through Google's consent message (UMP) where required, and you can change them at any time in the Application's Settings (where available). You can also reset or delete your advertising ID, or opt out of ads personalization, in your device's Android settings. The exact location depends on your Android version and device manufacturer; it is commonly found under Settings > Privacy > Ads (or Settings > Google > Ads).
Crash Diagnostics
To fix crashes and keep the Application stable across many different devices, the Application automatically sends crash reports to Firebase Crashlytics. A crash report may include your device model, operating system and version, app version, a Firebase installation identifier, and technical details about the error (such as stack traces). Crash reports do not include your health measurement results, and we do not collect your name, email address, or account information.
Usage Statistics (Firebase Analytics)
If usage statistics are enabled, the Application sends the following information to Firebase Analytics. If usage statistics are turned off, none of the items in this section are sent.
Device & Technical Information: Firebase Analytics automatically collects certain technical information about your device, such as hardware model, operating system and version, screen size and density, language and country settings, and app version. This information helps us ensure compatibility across different devices.
App Usage & Feature Statistics: We collect usage statistics to understand which features are used most and how they are used, so that we can prioritize improvements and optimize the features people rely on. This includes session events (such as app startup, closure, and session duration), which features are opened, the measurement method selected (e.g., Camera vs. BLE), the measurement duration and related feature settings, and ad loading status (success or failure). This is usage and configuration information only; your health measurement results are NOT included.
Connected BLE Device Information: When you connect a BLE heart rate device, the Application records the name of the connected device and its provided GATT service UUIDs to improve device compatibility and diagnose connection failures. Device names are set by the device manufacturer or by you and may therefore contain personal names. We do not collect or monitor ambient third-party Bluetooth devices.
Regional Detection Results: To evaluate the accuracy of the regional detection described below, we may log coarse country codes.
Time Check Results: If a mismatch between the device clock and network time is detected (see "Time Accuracy" below), we may log that event, without any health measurement data, so that we can understand how often this occurs and improve how the Application handles time.
The data in this section is pseudonymous: it does not include your name, email address, or account information, but it is linked to an identifier of the Application installation on your device.
Checks Performed by the Application
The following checks are needed for the Application to work correctly and are performed regardless of your usage statistics setting.
Approximate Location & Regional Compliance: The Application reads the country code reported by your mobile carrier network or SIM card (no location permission is required) for two purposes:
Default privacy settings: When you first open the Application, the carrier country code is read on your device to choose the default setting for usage statistics. This step does not use the internet, and the country code is not sent to us or to any third party.
Advertising availability: To determine whether advertisements can be served in your region, the Application uses the carrier country code. If it is unavailable, the Application sends a request to third-party IP geolocation services (e.g., ipinfo.io, country.is, ipwho.is, ipapi.co), which receive your IP address and return a country code. We use only the country code to comply with regional advertising restrictions, and we do not collect or store precise GPS location or your IP address. The result is stored on your device and re-checked only at limited intervals.
Third-Party Services & SDKs
To deliver advertisements in supported regions, handle analytics and crash diagnostics, and process purchases, the Application integrates the following third-party services, which may automatically collect advertising IDs, installation identifiers, and network request logs:
Firebase Crashlytics: Used to receive crash reports and diagnose stability problems.
Google Analytics for Firebase: Used to analyze feature usage and hardware compatibility when usage statistics are enabled. It may collect device identifiers, installation identifiers, and app usage statistics.
Firebase Remote Config: Used to adjust app settings and feature toggles remotely.
Google AdMob / Google Ads: Used to display advertisements within the Application in supported regions. AdMob may use device identifiers such as the Android Advertising ID to personalize ads and measure ad campaign performance, in accordance with your consent choices.
Google User Messaging Platform (UMP): Used to obtain and record your advertising consent choices where required (e.g., in the European Economic Area and the United Kingdom).
Google Play In-App Billing: Used to process one-time purchases and subscriptions. We do not collect or store your financial or credit card details; all transactions are securely handled by Google Play.
For more information on how Google uses data, please visit Google's Privacy & Terms.
Our support website is hosted on Blogger, a Google service. When you visit it, Google may use cookies and collect standard web log information (such as IP address, browser type, and pages visited), and may provide aggregated visitor statistics to us. We do not use the website to collect personal information from you directly. For more information, please see Google's Privacy Policy.
2. GDPR Compliance (For European Economic Area Users)
If you are a resident of the European Economic Area (EEA), you have specific data protection rights under the General Data Protection Regulation (GDPR).
Legal Basis for Processing: Our legal basis for usage statistics (Firebase Analytics) and for advertising is Consent. You can grant or decline consent for usage statistics through the Application's privacy notice and Settings, and for advertising through Google's consent message, and you may withdraw consent at any time. If you decline advertising consent, usage statistics are also turned off automatically. Our legal basis for crash diagnostics, and for the country-code and network-time checks needed for the Application to function correctly, is Legitimate Interests (maintaining a stable and lawful service).
Your Rights: You have the right to access, rectify, or erase personal data collected about you, as well as the right to data portability, to restriction of processing, to object to processing based on legitimate interests, and to withdraw your consent at any time. Because we do not collect your name, email address, or any account information, the data described above is pseudonymous and we are generally unable to identify which data relates to you. If you wish to exercise your rights, please contact us at the email address below and include information that allows us to identify the relevant data (for example, your Firebase app instance ID, if you are able to provide it). You can also stop optional data collection at any time by turning off usage statistics in the Application's Settings, by changing your advertising choices, or by resetting or deleting your advertising ID in your Android settings.
Data Transfers: Data processed by Google services may be transferred to and stored on servers located outside the EEA (e.g., in the United States). Google utilizes Standard Contractual Clauses (SCCs) to ensure adequate data protection.
3. CalOPPA Compliance (California Online Privacy Protection Act)
In accordance with CalOPPA, we agree to the following:
Users can visit our app store page and view this privacy policy anonymously.
Our Privacy Policy link includes the word "Privacy" and can easily be found on the Google Play Store listing and within the Application's settings menu.
Do Not Track (DNT) Signals: We do not track users over time and across third-party websites, and therefore the Application does not respond to DNT signals. However, some third-party tools used in the app may track your activities.
4. Children's Privacy (COPPA Compliance)
The Application is not intended for use by children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe that your child has provided personal information to us or to third-party services within our app, please contact us immediately, and we will work to delete that information.
5. Subscriptions and Purchases
All financial transactions, whether one-time purchases or recurring subscriptions, are handled entirely by the Google Play Billing Service. We receive confirmation of your purchase status from Google, but we never have access to your payment methods, credit card numbers, or billing addresses.
6. Changes to This Privacy Policy
We may update this Privacy Policy from time to time. Any changes will be posted on this page, and the "Last Updated" date at the top of this document will be revised accordingly. We will not send separate notifications, so we encourage you to review this page periodically. Your continued use of the Application after changes are posted means that you accept the updated Privacy Policy.
7. Contact Us
If you have any questions, concerns, or requests regarding this Privacy Policy or your data privacy, you can contact us at:
Email: twilightsirius17@gmail.com
