It is a steal, even at $10. This app is a successful implementation of Peterson's virtual strobe proprietary technology. The application compares very favorably with my original 490 and my StroboStomp 2.

I am a professional musician and stringed instrument tech, and even though I can tune to within 5 cents by ear, this is an invaluable tool to constantly have in my pocket. To the reviewer that defiled the ratings out of ignorance because it's "IOS 11 only" - if you have a legacy device, as I do, the workaround is to buy the application through iTunes on a computer, then "get" from the App Store on your device. To the others who removed a star because it doesn't have a pitch pipe or metronome - where in the description does it claim these features?

This is a tuner, and a damned good one. A used replacement for my StroboStomp would be $70. Many naysayers here probably have a $100+ Boss TU-2 on their pedal board (it is crap, has no pitch pipe or metronome, and employs LEDs to get guitarists vaguely close, yet nobody's whining to Roland) Sorry to bristle at ignorant reviewers, but they detract from the quality of this tool. Get it, and tune up already!