Simple Guitar Tuner

Play a string. It tells you which way to turn the peg. That's the whole app.

What it does

Tunes all six strings: Standard tuning — E2, A2, D3, G3, B3, E4 — referenced to A4 = 440 Hz. Pick a string, or let Premium follow whichever one you play.
Accurate to the cent: Pitch is measured on your device and shown to the cent. A string counts as in tune within five cents of target.
Private by design: Audio is analysed in the moment and never recorded, stored, or sent anywhere. The app has no networking code at all.