**Effective Date:** [2016-08-14]
**Last Updated:** [2016-08-14]
Juchen Investment Management, LLC ("we", "us", or "our") operates the **Lux Meter** mobile application (the "App"). This Privacy Policy explains how the App handles information when you use it on your Android device.
We have designed Lux Meter to be a **fully offline, zero-data-collection utility**. Reading this policy will be quick because there is very little to disclose.
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## 1. Information We Collect
**We do not collect, store, transmit, or share any personal information or personally identifiable information (PII).**
Specifically, the App does **not** collect any of the following:
- Name, email address, phone number, or any other identity data
- Device identifiers (e.g. Advertising ID, IMEI, MAC address, Android ID)
- Location data (GPS, network, IP-based, or otherwise)
- Contacts, calendar, photos, files, or media
- Camera or microphone input
- Crash reports, analytics, or usage telemetry
- Account credentials of any kind
The App does not include any third-party SDKs that perform tracking, advertising, analytics, or remote logging.
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## 2. Permissions
**The App does not request any Android runtime permissions.**
Lux Meter functions entirely using the device's built-in ambient light sensor, which is accessible to any application without a permission request and without exposing any personal information about the user.
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## 3. Sensors and On-Device Processing
The App reads values from the device's **ambient light sensor** in real time to display the current illuminance (in lux) on the gauge. These sensor values:
- Are processed entirely on your device
- Are held only in volatile memory during use
- Are **never** stored persistently, logged, exported, or transmitted off the device
When you close the App or send it to the background, sensor readings are discarded.
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## 4. Local Storage
The App stores a single, small piece of **non-personal technical data** locally on your device using Android's standard `SharedPreferences` system:
- Your **theme preference** (one boolean indicating whether you chose Day or Night mode)
This preference data:
- Stays exclusively on your device
- Is not associated with any account or identifier
- Is not transmitted to any server
- Can be erased at any time by clearing the App's storage in Android Settings or by uninstalling the App
All other sensor readings (including the session minimum and maximum values shown on screen) are held only in volatile memory during use and discarded when you close the App.
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## 5. Network and Internet Access
The App does **not** make any network requests. It functions fully offline. No data leaves your device because there is no code path that transmits anything.
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## 6. Third-Party Services, Advertising, and Analytics
The App does **not** integrate any of the following:
- Advertising networks (no ads of any kind)
- Analytics frameworks (Firebase Analytics, Google Analytics, etc.)
- Crash reporting services (Crashlytics, Sentry, etc.)
- Social-network SDKs (Facebook, Google Sign-In, etc.)
- Push-notification services
- In-app purchase or payment processors
The App is delivered as a standalone APK with no embedded third-party data collection.
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## 7. Children's Privacy
The App is suitable for users of all ages. Because the App does not collect any personal information, it does not knowingly collect information from children under 13 (or the equivalent minimum age in the user's jurisdiction). The App complies with the U.S. Children's Online Privacy Protection Act (COPPA) and applicable equivalents in other jurisdictions by the simple fact that it collects nothing.
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## 8. Data Security
Because no personal data is collected or transmitted, there is no personal data to be lost, stolen, or breached. The only data the App writes is a local theme-preference boolean, which is protected by Android's standard application sandbox and is accessible only to the App itself.
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## 9. International Users (GDPR, CCPA, and Equivalent Laws)
Lux Meter is available globally. Since we do not collect or process any personal data:
- **GDPR (European Economic Area):** We do not act as a data controller or data processor in respect of any personal data.
- **CCPA / CPRA (California, USA):** We do not "sell" or "share" personal information, because no personal information is collected.
- **LGPD (Brazil), PIPEDA (Canada), PDPA (Singapore), APPI (Japan), and other regimes:** No personal data is processed.
You retain full control over the only data the App generates (your local theme preference), which you can erase at any time as described in Section 4.
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## 10. Accuracy Disclaimer
Lux Meter displays illuminance values reported by your device's **ambient light sensor**. This sensor is designed by the device manufacturer primarily for automatic screen-brightness control, not for professional photometry. Readings are **estimates**: accuracy varies between device models, and factors such as sensor placement, screen protectors, or cases covering the sensor opening can affect the measured value.
Lux Meter is suitable for everyday, order-of-magnitude light assessment (checking whether a desk, room, or growing area is dim, adequately lit, or bright). For activities that require certified accuracy — such as workplace-safety compliance, professional photography metering, or laboratory measurement — please use a dedicated, calibrated lux meter instrument.
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## 11. Changes to This Privacy Policy
We may update this Privacy Policy from time to time, for example to reflect changes in the App, in applicable laws, or in Google Play requirements. When we do, we will update the "Last Updated" date at the top of this document. If a future update materially changes how the App handles information, we will make reasonable efforts to communicate the change through the App's store listing.
We recommend reviewing this Privacy Policy periodically.
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## 12. Contact
If you have any questions or concerns about this Privacy Policy or about Lux Meter in general, please contact us:
- **Email:**lameizhang66@gmail.com
- **Developer:** Juchen Investment Management, LLC
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*This Privacy Policy is published in English. In case of translation, the English version prevails in the event of any inconsistency.*