Sound/Light/Gradienter/Magnetic/Compass meters are built in this application.

This display screen will show the minimum/maximum/average/current values.

Reset button is used to reset all minimum/maximum/average/current values to zero.
Pause button is used to pause a meter. It will stop that meter. It can reduce the power consumption if you don't need use that meter.

It could help you to check the your ambient environment.

Others :
1. The accuracy is very depened on your device, especially the light/magnetic meter.
2. If you find some value is too larger, it maybe affect health. Recommand to buy a real accurate meter to double check it.

Screenshots: