Some rooms feel wrong. Cold, watched, uneasy.
There is often a physical reason for it. Sound too low to hear can cause exactly that sensation — unease, a prickling on the skin, a sense that someone is there. So can a strong magnetic field, or a vibration you feel without noticing that you feel it.
I believe in ghosts. I've been on a lot of hunts and I'll keep going on them.
But every time, the first thing I want to know is whether something ordinary is making the noise — a fan, a boiler, wiring in the wall, traffic outside, the building settling. Ruling that out isn't the dull part of the hobby. It's the part that makes anything left over worth taking seriously.
I couldn't find an app that did that honestly. Most of them make things up. So I built this one.
— Tim, Frapply Studios
Eerie measures those things, and tells you plainly what it found.
HOW IT WORKS
Put your phone on a hard surface, start a session, and leave the room. Eerie spends about 45 seconds learning what that particular room is normally like — every room has its own hum, its own field, its own background — and then watches for anything that departs from it
• Infrasound at 17–20 Hz, the range most often linked with unease
• Magnetic field, calibrated, in microtesla
• Vibration, through whatever surface the phone rests on
• Audible sound, logged as levels and never recorded
WHAT IT WILL NOT DO
Nothing in Eerie is randomised. There are no word banks, no entity readings, no invented results. It reports what the sensors read and nothing more, and it will never tell you a room is haunted.
Every event it records is listed with the ordinary causes that most often explain it — a fridge compressor, a boiler, wiring in the wall, traffic, a notification on your own phone. When several channels move at once it says so, because several measurements agreeing is genuinely stronger than any one of them alone.
And when nothing happens, it says that too. "Nothing registered" is the result most sessions should produce, and it is the answer most other apps will not give you.
THE SESSION REPORT
Every session is saved on your device: a timeline of all four channels, a spectrum of the low frequencies across the whole run, the events with their likely causes, and a plain-English summary. Share it as an image if you want to. Nothing is sent anywhere unless you send it.
HONEST ABOUT ITS LIMITS
iPhone microphones are not calibrated below about 20 Hz, so Eerie never quotes an absolute sound level — only how far a reading has moved from the room's own baseline. It watches 17–20 Hz because that is roughly as low as a phone microphone usefully reaches. The questions section inside the app explains all of this.
PRIVACY
No accounts. No tracking. No analytics. No data collected, ever. Audio is turned into numbers as it arrives and discarded immediately — it is never recorded, stored, or transmitted. Nothing you measure leaves your phone.
ONE PAYMENT
Eerie is a single purchase, not a subscription. Buy it once and it stays bought, on every device signed in to your Apple Account. No trial, no renewal, nothing to cancel.
Privacy Policy: https://sudsy-colony-9c9.notion.site/Eerie-Privacy-Policy-3d4c0f3b6281804e9757ed56d613c869