Good, with manageable quirk
I changed my rating from five stars to two because I got a new iPhone XR and it doesn’t not work on it. I went to settings to turn the microphone on, but it didn’t prompt me to allow this app access. The app probably needs to be updated for new models of phones. Below is my previous review: Does not pick up my low E string. I just fret up 5 and it detects it as an A. I have paid more than $30 for a stand alone tuner that I have had to manage the same way. Useful and simple and always with me.