Good but not awesome.
I also have the strobosoft virtual strobe tuner software on my iMac, and like it, this simation is good. However, its not necessarily $10 better than some of the free tuning apps. The app frequently locks up and sometimes cant track the note being plucked. Im really hoping that a future update will fix the problem.
KissTone about
iStroboSoft, v2.3