I was surprised how far to push my car stereo settings--nice! – Spectrum Analyzer RTA Review

Seems to work best if I attach the iPhone to the car via USB for pink noise generator, and use iPad for spectrum analysis. Doing both on the iPhone alone, the iPhone noticeably diminished the pink noise volume. I used iPhone 7+ and iPad Pro with iOS 10.3.2, and the screen is completely steady. Even with the iPhone 4S, the screen is completely steady.
Review by Don A7 on Spectrum Analyzer RTA.