iPhone speaker - room setup apps

Audio Tool: Suite of Decibel Meter Pro 2, Microphone Pro, Tone Generator Pro, Scope Pro. Very useful set of apps from Performance Audio. A pro audio company.

RTA Audio: Real time spectral analyzer The free version is listed as RTA Audio Free in the app store. Try the free version, then buy the $6.95 version. The paid version has higher resolution and a continuous line instead of bars. 20 to 20 kHz Many options! Great room setup tool!
is the quality of the mic built-in the iPhone good enough for this type of thing??
There are plenty of adjustments in these apps to compensate for the iPhone microphone.

They can be calibrated with professional equipment, but for home audio use they are more than acceptable as is.