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!