Great, but inconsistent at lower octaves.
I got this app to tune my Piano, and it was very consistent throughout the middle octaves. The issue though, came with the lower octaves. There were constant irregularities, like for example recording a clear A0 as an A2. There were also some issues with the higher octaves such as C6 and upwards, though not as severe as the lower octaves. A final issue I would like to point out is how it can sometime not register sound at all after extended use of the app, and it would only work again after restarting it. Despite the negatives, I still give it 4 stars since most of the issues arent likely the apps faults but likely due to the microphone not being sensitive enough. I would recommend the app.
Ancient Promethean about
TonalEnergy Tuner & Metronome