What is the best alternative to AudioTools, dB, Sound & Audio on iPhone?

Decibel X:dB Sound Level Meter, S tier, #1 in audio analysis.

Is there a free alternative to AudioTools, dB, Sound & Audio?

Yes: Decibel X:dB Sound Level Meter (S tier, #1) is free to download.

Yes. 1 app ranks above it in audio analysis: Decibel X:dB Sound Level Meter (#1).

AudioTools, dB, Sound & Audio is A tier, #2 of 6 in audio analysis. Here is everything that competes with it on iPhone, in tier order.

1
Decibel X:dB Sound Level MeterShigher tier
Free download · ★ 4.6 · 163,256 ratings · score 97
Turns an iOS device into a sound level meter that measures sound pressure level in dBA and dBC, with history, graphs…
3
Decibel : dB sound level meterA
Free download · ★ 4.6 · 36,148 ratings · score 87
Sound level meter that measures ambient noise in dB in real time, with a built-in spectrum analyzer.
4
Decibel X PRO: dBA Noise MeterA
$69.99 · ★ 4.7 · 6,918 ratings · score 86
Turns an iOS device into a sound level meter that measures sound pressure level in dBA, dBC and other weightings.
5
Decibel Meter UltraA
Free + IAP · ★ 4.6 · 2,546 ratings · score 83
Sound level meter that measures, records and logs noise levels, with dosimeter and octave band analysis tools.
6
Audio Spectrum Analyzer dB RTAB
Free + IAP · ★ 4.5 · 3,040 ratings · score 75
Real-time audio spectrum analyzer and sound level meter with FFT plot and octave band (RTA) views.

What is the best alternative to AudioTools, dB, Sound & Audio on iPhone?: Decibel X:dB Sound Level Meter, S tier, #1 in audio analysis.
Is there a free alternative to AudioTools, dB, Sound & Audio?: Yes: Decibel X:dB Sound Level Meter (S tier, #1) is free to download.
Does anything rank above AudioTools, dB, Sound & Audio?: Yes. 1 app ranks above it in audio analysis: Decibel X:dB Sound Level Meter (#1).