The EMF side reads your device magnetometer (DC field) and plots change as milligauss so it behaves like a ghost-hunting K-II, which is an AC meter. The spirit box is a band-pass sweep through noise — the software analogue of a radio scan, not AM/FM hardware. Headphones recommended.
EMF meter
tap Arm sensors
0.00 µT change · DC — · heading — · |a| —
Earth’s static field is tens of µT and would peg a naïve meter. This one zeros on the room, then lights LEDs when the field moves — walk a magnet past the phone. Chrome on Android is the real magnetometer path; iPhone often only gives compass/motion.
Spirit box
Swept band-pass · white noise · scan lamp off
A hardware spirit box is a radio left in scan so fragments of stations bleed through. Browsers cannot open the AM/FM tuner. This box sweeps a noisy band-pass the same way DIY software boxes do. It will invent syllables. Treat hits as hits on a toy, then go verify in the room.
Gravitational-wave catalog
Public LIGO / Virgo / KAGRA events · …
A phone cannot detect astrophysical gravitational waves. The plot is a reconstruction of catalogued chirps from GWOSC.