DecibelwerkFeatures
Four instruments in one app. All of them run on your iPhone, and none of them records or uploads sound.
Sound level meter
A-weighted decibel meter with a backlit VU needle, Leq, min, max and the NIOSH safe time.
Free
Tone generator
Sine, square, saw and triangle from 20 Hz to 20 kHz on a knurled tuning knob, with a 20 Hz–20 kHz sweep.
Free (sweep with Pro)
Speaker cleaner
A pulsed 165 Hz tone for 30 seconds that shakes water drops off the speaker grille.
Free
Noise logs and reports
Records the level once a second for up to 8 hours; PDF report with Leq, Max, L10, L90 and dose.
3 free logs, then Pro