In the past few years, we have covered a bunch of cool tools that turn an iPhone into a thermal imager. The Seek LT-AAO Thermal Imager for Otterbox uniVERSE is also worth a look. It is a compact solution that lets you see in total darkness on your phone. You get a 206×156 sensor with a 20-degree narrow field of view.
Compact for Otterbox uniVERSE case not only enhances your phone, it doesn’t compromise its protection. It can detect temperatures from -40C to 330C.[where to get it]