Review

The device works well. At first sight, it achieves the advertised resolution and accuracy.

The field of view is wide enough so as to allow many applications including PCB inspection, checking your house isolation (indoor and outdoor), checking your car (engine/brakes), checking electrical devices (freezer, TV, ...), and so on. The wide field of view is not optimal for wild life observation since it results in a panoramic view instead of a zoomed-in view.

The biggest problem with the T2S+ is the "xtherm infrared" app: currently it cannot be found on the play store, so it needs to be side loaded.
To side load the app: look for "apk infiray t2s+" on the internet, download the apk on the phone, and use an apk-installer to install it.
Note: side loading + installing the app requires some expertise and patience, is less secure, prevent automatic app updates, and is a bit frustrating. But in the end it works.

The positive thing about InfiRay and the T2S+ is that they support open source solutions, so there exist for example a python script to use the T2S+ on Linux (for Windows, InfiRay provides software, but I guess that python script would also work).

Resources I used:
https://dmytroengineering.com/content/projects/t2s-plus-thermal-camera-hacking
https://apkcombo.app/xtherm/com.infiRay.Xtherm/