SUS4 Tuner

In tune in seconds. Every instrument, every note.

SUS4 Tuner is a chromatic tuner built for anyone who plays — guitar, bass, ukulele, violin, brass, woodwind, or anything in between. Open the app, play a note, and the needle settles on pitch before your hand is off the string.

The A4 reference is adjustable from 430 to 450 Hz so you can match any ensemble, pit orchestra, or recording session. Compact view keeps things simple; Stage view enlarges the display so you can read it from a music stand across the room. The Apple Watch companion means you can tune without touching your phone at all.

• Chromatic tuner — accurate to the cent • Instrument presets: guitar, bass, ukulele, violin, brass, and woodwind • Adjustable A4 reference: 430 to 450 Hz • Cents readout so you know exactly how far off you are • Compact view for everyday use; Stage view for the music stand • Apple Watch companion — glance, tune, play • Subscribe monthly, or unlock the full SUS4 suite forever: alternative tunings and brass/woodwind presets

The tuner runs entirely on your device. No audio is ever sent to a server. No account needed.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/