Good
Dec 10th is good. I hear that other paid apps are more accurate, but I dont know that and find D 10th seeming to be on target, and I am a professional. It would be good to know how it is set and how accurate it is. Otherwise my only suggestion would be that the written labels at top freeze a couple seconds on the most dominant volume (like a peak meter): "conversation," "inside auto," etc.
Really like the app otherwise. As you upgrade, dont toss out the main features you have now (readout, bottom left and right, analog, scroll, all are good).
Hepsound about
Decibel X:dB Sound Level Meter, v5.1.1