GhostTrail: Sensor Logbook

A logbook for places that feel wrong. Capture environmental sensor anomalies — magnetometer, accelerometer, GPS — and share what your phone actually measured.

A logbook for places that feel wrong.

Walk into a room that gives you that feeling. Tap once. Hold still for two seconds while the rig baselines. GhostTrail starts reading your phone's magnetometer, accelerometer, and GPS — for up to sixty seconds, or until you tap stop.

You get a pin you can keep on your phone, or share to the World Map so other spotters can see what your phone measured.

WHAT IT IS • An honest sensor recorder. The readings are what the phone measured. Nothing else. • A logbook with retro VHS chrome. Each capture earns a tape number, a phosphor-green status readout, and — for curated landmarks — a multi-section lore card you can export as an Instagram Story sticker. • A curated map of nearly 200 places across six continents — locations known for the kind of stories that make people lower their voice.

WHAT IT IS NOT • A ghost detector. The app never interprets readings. It logs them. • A microphone recorder. The permission is never requested. • A tracking app. No advertising identifiers. No analytics. No third-party trackers.

SIGNALS — THE PEEK ECONOMY Opening another spotter's public pin costs one Signal. You start with three free Signals, and every pin you publish yourself earns one back — no daily caps, no limits. Out of Signals? Publish your own pins, or buy a Signal pack from Profile → SIGNALS. Three pack sizes: 3, 12 (+25% bonus), or 30 (+40% bonus).

PRIVACY BY DEFAULT • Captures stay on your phone by default. Nothing leaves the device until you tap SHARE TO WORLD MAP. • Shared coordinates are fuzzed by ±30 meters before upload. Precise location never leaves the device. • Sign in with Apple is the only auth method. Apple's private email relay is supported. • Profile → Delete account permanently removes everything you have shared.

FOUR TIERS OF ANOMALY Quiet · Stir · Pulse · Surge. The same readings, four amplifications of chrome. Your screen reacts to what the rig is seeing. A haptic pulse fires on every tier crossing. No sound is ever played.

DESIGNED FOR LATE-NIGHT USE Phosphor green on near-black. Retro VHS scanlines. Monospace timecode. The interface stays out of the way.

REQUIREMENTS • iPhone running iOS 17 or later • Magnetometer (every modern iPhone has one) • Location and motion permissions, granted on first capture • Camera permission optional — only for photos attached to pins • Photo Library Add permission optional — only when saving an Instagram-bound landmark sticker

GhostTrail does not detect ghosts. It logs environmental sensor readings as data, not as paranormal claims.