Free, ad-free, tracker-free utilities that state what they cannot do as clearly as what they can.
A sound level meter that tells you how much to trust its own reading. Every measurement shows its margin of error. One screen names the four things limiting it on your phone:
It measures in dBA, dBC and dBZ, with the standard time responses. Octave bands and exposure tracking against the NIOSH and OSHA limits are there too.