This small thermal camera plugs into either some iOS devices or some Android ones (depending which version you buy).
The FLIR ONE turns any compatible Apple (iOS) or Android mobile device into a high performance thermal imaging camera.
The FLIR ONE is ideal for DIY enthusiasts, technology geeks, or as an entry level thermal camera for professionals and tradies. It features:
Superior image quality with MSX Technology
Built-in battery for no reduction in handset battery life
Protective case included
Take still photos, thermal video, panorama images, and thermal time-lapse.
https://www.youtube.com/watch?v=AlH3yYkCqE0
Seems quite effective for looking for hot spots around the house. I've only had a quick fiddle so far but it looks handy.
$20 cheaper??