• Last updated: 7 September 2026

Eerie collects no data about you. There are no accounts, no analytics, no

advertising, no tracking, and no third-party SDKs of any kind. Nothing you measure

leaves your phone.

This policy is short because there is very little to describe.

What Eerie measures

Eerie is an environmental measuring instrument. While a session is running it reads

four things from your iPhone's own sensors:

• Sub-audible sound (infrasound) from the microphone
• Audible sound level from the microphone
• Magnetic field strength from the magnetometer
• Vibration from the accelerometer

All of this is processed on your device, in real time.

The microphone

Eerie needs microphone access to measure sound. This is the part people most want to

be clear about, so:

• Audio is never recorded. Sound is converted into numbers — frequencies and levels

— as it arrives, and the audio itself is discarded immediately. Nothing is written to