Aetherometer

Aetherometer puts three instruments for Earth's field in one app, ordered by scale. LEYLINE: In your hand Reads your phone's magnetometer and shows the local magnetic field in microtesla. Run a survey on foot and record it. Surveys can be exported as GPX. EARTHTUNE: Planet-wide Shows the Schumann resonance fundamental in hertz from the EarthTune observatory feed, and lets you listen to it. LIMEN: At the boundary Shows the magnetopause standoff distance in Earth radii. It is modeled from NOAA SWPC solar wind data using the Shue 1998 model, and the app labels it as modeled. THE BELT The home screen shows all three readings at once. Open an instrument and a bar lets you go back or jump straight to another one. A listening session keeps playing and a survey keeps recording while you look at a different instrument. HONEST BY DESIGN Each reading is marked as live, modeled, stale or sample, so a modeled value never passes for a measurement. Location is used only while a survey or its map is open, and there is no background location mode. Leaving the app pauses a survey and records a gap. Works on iPhone, iPad and iPhone Duo. One purchase, everything included. No ads, no in-app purchases, no locked features. Note: the magnetometer is built into your iPhone. Readings depend on your device's sensor and nearby metal or electronics.