This is the camera: https://www.flir.co.uk/products/flir-one-pro/
Just download the app – “Flir” – and plug the camera into your iPhone / iPad. You’ll see the thermal image on screen, and can press the button on your screen to take photos, which are saved in the normal photo library.
It’s a great way to see if your cavity wall or loft insulation has been installed properly, find cold spots, or see which elements of your building could do with better insulation. Contact Simon on email@example.com or 07889 379 910 if you’re interested in borrowing it . Simon has said he’s keen for it to get as much use as possible.
Here are some example pictures from Simon’s house: