Calibre: Watch Collector
Mechanical Watch Timegrapher
Free · In‑App Purchases
Calibre is a precision instrument for your pocket — a software timegrapher that measures the accuracy of mechanical watches using your device's wired or built-in microphone.
Place the microphone so that it can pick up the sound of your watch/movement and Calibre begins listening immediately. The escapement's tick and tock are detected in real time and the app computes the same measurements as a physical paper-tape timegrapher:
• Rate deviation — seconds per day gained or lost relative to nominal
• Beat error — asymmetry between the tick and tock intervals in milliseconds (preview)
• Amplitude — the arc of the balance wheel in degrees (preview)
• BPH — the beat frequency of the movement, detected automatically or set manually
A scrolling paper-tape trace gives you a live visual of timing consistency. An ensemble beat waveform view overlays averaged tick and tock cycles for detailed acoustic inspection. Confidence bars and real-time signal quality indicators guide you to the best microphone placement.
WATCH LIBRARY
Build a library of watches/movements with individual profiles — lift angle, nominal BPH, caliber notes and full measurement history. Measurements are grouped by dial position when you measure the same watch in multiple orientations and a rate history chart shows how accuracy changes over time. Service events mark the start of a new era so pre-service data is retained but excluded from current analysis.
REAL-WORLD COMPARISON
Manual timing runs let you log (real time, watch time) pairs over hours or days. Linear regression computes drift rate, current offset and R², letting you compare bench measurements against the watch's actual performance on the wrist.
AUDIO PIPELINE
Separate DSP profiles for built-in, wired and Bluetooth microphones switch automatically when the audio route changes. Optional AudioKit Butterworth filters, software AGC, adjustable detector threshold and envelope release give you precise control over how the signal is processed. An on-demand signal analyser inspects the live audio feed and suggests filter and gain settings as individually-appliable cards.
FULLY OFFLINE
No account required. No network requests. No analytics or telemetry. All measurement data stays on your device.
Calibre is designed for watch enthusiasts, collectors and watchmakers who want data at their fingertips.
LEGAL
Privacy Policy: https://calibrewatch.app/privacy
Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Welcome to Calibre 1.3.
MORE ACCURATE AMPLITUDE
Amplitude is now measured from an average across many beats instead of one beat at a time. Readings are steadier, quiet watches measure more reliably and movements that used to pin the reading at 360 degrees now report correctly.
BETTER WEB CAPTURE
Extracting specs from a product page now pulls dimensions (lug to lug, lug width, thickness), weight and price. AI enrichment fills gaps and corrects the scrape. Preview the extracted fields before applying and tap any you want to skip.
PDF EXPORT & SAVE TO FILES
The PDF report is a clean one-sheet with your watch photo, comprehensive specs and a performance summary. Save it directly to a Calibre folder in the Files app.
WATCH DETAIL & PHOTOS
Tap the hero photo to view it full screen with pinch-to-zoom. Find Image fetches product photos from the URL so you can pick one without leaving the app. Paste Image now works reliably on all iOS versions.
ALSO
- Filter the Watches list to Have, Want or All with one tap
- Retail price and estimated value fields on each watch
- Select and copy spec values from the watch detail screen
- Sub-second drift rates show two decimal places
- iPad: controls no longer overlap the tab bar
- VoiceOver improvements across the measurement screen
- Updated Spanish and French translations
The developer, Tim McNerney, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Tim McNerney
- Size
- 10 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later.
- iPhone
- Languages
English and 2 more
- English, French, Spanish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Calibre Pro Annual $4.99
- Calibre Pro $14.99
- Copyright
- © 2026 Oneofus

