Good and bad?
I downloaded a dozen of these sound pressure level meter apps. Most give obviously wildly inaccurate results like 80 dB in a quit room with no talking. Insane. This app gives nearly identical results when similtaneously running on iPhone and iPad. The results were not only almost identical but believable with quiet room readings in the 35-40 dB range. All good. The bad. The apps description talks about a setup or setting screen where you can calibrate the microphone. I can't find a setting screen or page anywhere.