Do you have experience with "infrared camera detection" on mobile devices?

If so, how do you assess the difference between
o How the infrared camera detection works on a mobile device, versus
o Similar functionality, in almost _any_ digital video camera viewfinder?

Note this question is only about the inherent infrared detection
differences between almost any digital camera ... and these "green-screen"
viewfinder apps.

Today I decided to check an area for hidden cameras and microphones
where the first non-obnoxiousware non-Internet non-GPS-aware
free tool I happened to test was
o Detect Hidden Camera, version 1.9
o (com.techno95.detecthiddencameraandmicrophone)

The way "it" works is pretty simple, apparently, where
o It detects rf emitters using the magnetometer reading, and
o It detects infrared emitters using a "green screen" video viewfinder

Based on an Internet search, these tools abound on both iOS & Android:
https://knowtechie.com/smartphone-apps-can-help-detect-hidden-cameras-anywhere/
https://www.techzac.com/best-hidden-camera-detector-apps-android/
http://www.graphictunnel.com/2017/09/best-hidden-camera-detector-apps.html
etc.

My question for this newsgroup is only about that green-screen viewfinder.
Q: Essentially, other than being "green" - how is it any different from
almost _any_ digital video viewfinder (all of which seem to detect infrared
emissions)?