Isochron: Watch Timegrapher

See how accurate your mechanical watch really is. Isochron uses the iPhone microphone to measure rate, beat error, and stability. Nothing is recorded or sent off-device. WHAT YOU GET • Rate in seconds per day — the number you actually compare between wears • Beat rate from vintage 18,000 BPH to hi-beat 36,000 BPH • Beat error in milliseconds (tick vs tock) • Stability as the reading settles • Amplitude as an estimate, labeled honestly — not a bench-machine claim SIX POSITIONS, ONE MOVEMENT Dial up, dial down, crown up, crown down, crown left, crown right. Spot positional drift before you book a service. A PROFILE FOR EVERY PIECE Save brand, model, reference, movement, and serial. Each measurement stays with that watch so you can see if it is wandering over days and weeks. HOW TO MEASURE 1. Find a quiet room. 2. Hold the watch 5–15 cm from the iPhone microphone, or rest the crown near…