Four iPhone timegrapher apps compared
Hairspring, Timegrapher X, Oscillo, and Isochron all listen to a mechanical watch, but they are built around different decisions. The useful choice is between measurement rigor, long tests, or a broader collection app—not four versions of the same tool.
Short answer: choose Hairspring when you want uncertainty, a required second run, and a saved agreement verdict. Choose Timegrapher X for its established instant and long-test workflow. Choose Oscillo for a broad, cloud-capable collector suite. Choose Isochron for acoustic timing plus photo-based drift and community comparisons.
Disclosure and method: this page is published by Hairspring's developer. It compares features stated in the apps' current US App Store listings and official sites; it is not a head-to-head accuracy test. Prices and compatibility were checked August 28, 2026 and can change.
At-a-glance comparison
| App | US starting price | Minimum iOS | Primary emphasis | Best fit |
|---|---|---|---|---|
| Hairspring | $9.99 upfront; no in-app purchase | iOS 18.0 | Rate uncertainty, second-run agreement, reasoned refusals, position sessions, and PDF evidence | You want a narrow measurement instrument that states what its evidence can support. |
| Timegrapher X | $29.99; optional Pro in-app upgrade | iOS 18.0 | Instant timing, detailed diagrams, and long tests; optimized around a wired EarPods microphone | You want an established phone timegrapher with extended recording and export options. |
| Oscillo | Free download; in-app purchases and subscriptions | iOS 26.0 | Timegrapher, collection management, AI identification, precision tracking, and optional cloud sync | You want timing inside a wide collector and watch-management suite. |
| Isochron | Free download; optional one-time Pro purchase | iOS 17.6 | Acoustic timing, photo-based wrist drift, collection records, position tests, and community comparison | You want both short bench-style readings and longer real-wear context. |
What each app is designed to answer
Hairspring: “Did the measurement repeat?”
Hairspring reports rate with statistical fit uncertainty, beat error, BPH, and a live amplitude range. It then asks for the same setup again and states whether the two rate estimates agree. Unsupported signals produce a refusal and a suggested fix. History, six-position sessions, comparisons, and PDF receipts are included in one purchase. There is no account, subscription, in-app purchase, advertising, analytics, or automatic upload.
Timegrapher X: “What happens now—and over a long test?”
Timegrapher X has instant and long-test modules, a real-time waveform, and a detailed timing diagram. Its listing recommends pressing a wired EarPods microphone against the watch for stronger pickup. The optional Pro upgrade adds branded PDF reports, CSV export, and long measurements up to 120 hours.
Oscillo: “How does timing fit into my collection?”
Oscillo combines rate, beat error, amplitude, BPH, position records, and multi-day precision tracking with collection management, watch identification, reports, reminders, and sharing. It can start without an account and work offline; its listing also describes optional cloud sync and both subscription and lifetime purchases. Its iOS 26 requirement is the key compatibility check.
Isochron: “How does the bench reading compare with real wear?”
Isochron combines a microphone timegrapher with a photo method for measuring drift over longer periods. Its free tier includes measuring, collection records, the photo method, and community features; its one-time Pro purchase adds amplitude, guided position tests, overnight runs, a magnetism check, and an insurance report.
Do not choose from the headline number alone
Every phone timegrapher depends on the watch, position, state of wind, room, surface, microphone path, and detector. A screen that shows more decimal places does not by itself contain more evidence. Whichever app you choose, repeat the same setup before interpreting small differences and compare several positions before judging the watch.
The guide to reading a timegrapher explains rate, trace, beat error, amplitude, and BPH in order. The free repeatability calculator lets you compare two rate estimates and their uncertainties even if you do not use Hairspring.
If you are deciding between these installed apps and a zero-install web tool, the separate free online timegrapher vs iPhone app guide compares microphone control, repeatability, saved evidence, cost, and the role of a bench machine.
Try the measurement-first option
Hairspring is deliberately smaller than a collection platform. Its job is to measure, disclose uncertainty, make you run the test again, and preserve the evidence without an account or subscription.
One $9.99 purchase. No subscription, in-app purchase, account, ads, analytics, or automatic uploads.
Frequently asked questions
What is the best iPhone timegrapher app?
There is no universal best choice. Match the app to your question: repeatable measurement, long testing, collection management, or real-wear drift.
Which app checks whether two readings agree?
Hairspring explicitly asks for a second run, carries the statistical fit uncertainty from both rates into the comparison, and saves the agreement verdict.
Can one of these replace a bench machine?
A phone can handle many portable checks, position comparisons, and records. Use a controlled contact pickup and stable holder for movement regulation, repair, or any diagnosis where the setup must be tightly controlled.
Primary product sources
- Hairspring US App Store listing
- Timegrapher X US App Store listing and developer site
- Oscillo US App Store listing and developer site
- Isochron US App Store listing and developer site
Hairspring is not affiliated with Timegrapher X, Oscillo, or Isochron. Product names identify the compared apps. Corrections are welcome at moganes@gmail.com.