Touch GUI: Fully interactive touch GUI features includes scroll up/down, pinch to zoom or compress the vertical dB scale, or swipe horizontally to get a cursor that reads out the exact dB level and frequency across the screen. To make the cursor disappear, swipe it off the graph to the left. The landscape-mode display flips 180 degrees so that you can face the internal mic in either direction.

Calibration: RTA can be calibrated, and stores two calibration constants, one for the internal mic and one for the external calibrated test microphone. We even have corrected for the iPhone’s intrinsic high and low-frequency roll-offs.