Lux Meter is a free utility app developed by KHTSXR for Android devices that measures illuminance using the light sensor on your phone. The app is easy to use and provides accurate readings of the light level in lux values.

To use the app, simply hold your phone close to the light source you want to measure. Lux Meter will then display the illuminance level in lux values on your screen. The app has a dynamic range between 1 and 30,000 lux, making it suitable for a wide range of lighting conditions.

It's worth noting that the accuracy of the readings may vary depending on the device's light sensor. Some devices may not have a light sensor at all, while others may not be linear or as accurate. However, for most modern Android devices, Lux Meter provides a reliable and convenient way to measure illuminance.