HAIRSPRING — FACT SHEET
========================

App name        Hairspring: Watch Timegrapher
Developer       Marat Oganesyan (independent)
Released        August 2026 (current version 1.0.2)
Price           Paid upfront ($9.99 USD; localized by storefront) — no
                subscription, no in-app purchase, no ads, no account
Platform        iPhone, iOS 18 or later (iPhone only, by design:
                the measurement wants the handset lying flat with the
                watch beside the bottom microphone)
Privacy         App Store nutrition label: Data Not Collected.
                Audio is analysed on device and never transmitted.
App Store       https://apps.apple.com/us/app/hairspring-timegrapher/id6797146448
Website         https://kapella-hub.github.io/appstore/
Contact         moganes@gmail.com

ONE-LINER
Hairspring measures how well a mechanical watch keeps time, using the
iPhone microphone — and tells you when it can't.

WHAT IT DOES
- Rate in seconds per day, with statistical fit uncertainty computed
  from the actual scatter of the detected beats
- Beat error, measured from the escapement's own high-frequency signature
- Live amplitude, shown as a band, because that is what the acoustic
  method honestly supports
- Timing graph, position runs, measurement history, PDF measurement receipts
- Measure the same watch twice and Hairspring states whether the two
  readings statistically agree, then saves both readings, the verdict,
  and analysis version in History and the PDF

WHAT MAKES IT DIFFERENT
Hairspring refuses a rate it cannot defend. Too much scatter, an
implausible result, or timing too disturbed to number the beats produces
a stated refusal that names its cause and the fix — never a
plausible-looking wrong number. The analysis band its beat detector uses
was chosen by a pre-registered experiment: acceptance criteria written
down before the data was collected, with the first failed attempt
recorded as a failure.

NAME NOTE
Hairspring is unrelated to the discontinued watch-timing app of the same
name by another developer, which left the App Store years ago.

SCREENSHOTS
Every screenshot is the real app rendered by the shipping binary — the
project treats marketing the binary cannot reproduce the same as an
invented measurement. The figures shown are ones the project actually
measured.
