REF-440 Tuner

Tune with confidence. REF-440 delivers professional-grade accuracy in a beautiful, distraction-free interface that feels like a precision instrument, not an app.

REF-440: The tuner that disappears when you need to play.

REF-440 is designed for musicians who demand precision and clarity. Inspired by Dieter Rams and Teenage Engineering, every pixel serves a purpose. No ads. No clutter. Just a precision instrument that helps you tune and get back to making music.

Precision You Can Feel

REF-440 uses the McLeod Pitch Method (MPM) algorithm, optimized for real-time guitar tuning. With ±2¢ accuracy, adaptive smoothing, and intelligent note locking, you get stable readings that don't jump around — even in noisy environments.

Designed Like an Instrument

The interface mimics a hardware tuner: a dark "faceplate" display panel, needle meter with ghost trails, and LED indicator. The 135-point note display is readable from across the room. Orange means action, neutral means success.

Context-Aware Instructions

Forget "flat" and "sharp." REF-440 tells you what to do: TIGHTEN or LOOSEN for strings, TUNE UP or TUNE DOWN for chromatic mode. Physical actions for physical instruments.

Every Guitar Player's Needs

Guitar — 12 tuning presets including Standard, Drop D/C/B, Open G/D, DADGAD, and more Bass — Standard, Drop D, Half-Step Down, 5-String Ukulele — Standard (High-G), Low-G, Baritone Chromatic — Detect any pitch across the full frequency spectrum Thoughtful Customization

Reference pitch from 415 Hz (Baroque) to 466 Hz (bright orchestral) Capo support (0-12 frets) Sharp/flat display preference (A# vs Bb) Adjustable noise gate for any environment Optional in-tune chime (customizable sound) Keep screen on while tuning Premium Details

Standby mode saves battery — tap to resume Home screen and Control Center widgets (iOS 18+) Siri Shortcuts for reference tones Live Activity during tuning sessions VoiceOver accessible with meaningful labels Respects Dynamic Type and Reduce Motion settings Built for Musicians, by Musicians

REF-440 is a single-purpose tool that does one thing exceptionally well. No subscriptions, no premium upgrades, no feature gates. Just a tuner that works.