Good, but not great
This is an okay app for tuning a guitar, but it is lacking some functions that would make it more useful - mainly chord charts. I use mandolin tuner which includes a chord charts that is very useful. Another glitch is that the 2nd harmonic of the string being tuned displays about half of the time. Mandolin tuner doesn’t have that glitch. It’s a pity since I also paid for the in app purchases.