To See Infrared Radiation
Interestingly, you can use your phone to check whether the batteries of your remote control work well! To do that, you should grab your phone and switch on the camera app. Next, you should hold the Tv remote control, point it right at the camera and then press any button that crosses your sight.
A red light should appear if the batteries are still good! That’s not everything as you can also use your smartphone to create a flashlight out of a TV remote control!