Sound Meter HQ PRO is a free Android application developed by Just4Fun Utilities in the category of Utilities & Tools. The app uses the built-in microphone of the device to measure the sound level of the surrounding and displays the result in decibels on the screen. However, the app's disclaimer mentions that the tool should not be treated as a professional device to measure decibels as the built-in microphone is designed to capture human's voice and may not capture sounds above ~dB. Additionally, some devices may have Automatic Gain Control, which can also affect the measurement.

The app displays the measured noise level with the help of an indicator on the gauge, with loudness levels ranging from 0 to 140 dB. The application also displays the minimum and maximum registered level of the sound, which can be cleared at any time using the "Reset" button. Additionally, the app displays the noise power in a descriptive way, with sound measure thresholds ranging from 10 dB (Breathing) to 140 dB (Shotgun). If the user has access to a professional sound pressure level measurements device (SPL meter), they can use it to calibrate the app by setting the same value using the calibration menu in the app.