Unimpressed guitarist

I am surprised by the amount of good reviews and strong statements regarding the quality of this ap. While tuning my acoustic guitar, the meter jumps around, never settling down long enough for me to be sure if I have any given string tuned. I have explored the menu and tried many different orientations but still cannot get it to work right. I am not a newbie.. I normally use a Korg CA-30, a wonderful tuner. Perhaps Im used to its accuracy. Maybe its the iphones mic causing the problem? Dunno-
I wish Id saved my two bucks and bought a root beer instead:-/

GMLPC about PitchBot - Smart Chromatic Tuner