I think the best choice dB meter is must be the dB Meter which measures sound & noise level in Decibel. Decibel sound meter apps are reliable and efficient a powerful medium to measure the sound level in any circumstances.
Just look at the features it includes, you will definitely agree with me after seeing them.
● Highly accurate decibel meter.
● FFT Plot (Fast Fourier Transform)
● Linear and logarithm scales
● Up to 16384 FFT size (not all phones supported)
● A lot of available window functions
● Tracking for max noise volume value
● Max and Min decibel hold for any selected frequency
● Stunned graphics
With this all, dB meter is without any doubt the best at the moment.