Disaster City is your one-stop for about every catastrophe you can think of. Train derailments, hurricanes, and other unfortunate happenings all get simulated at the Texas A&M site. As part of a test Wednesday, first responders test piloted something new: a smartphone app that detects radiation.

GammaPix, which sounds like one of those weird apps you accidentally find in the App Store and assume doesn't work, is apparently a real thing for iPhone and Android that "can be used for the detection of radioactivity in everyday life such as exposure on airplanes, from medical patients or from contaminated products." It works through a smartphone's camera, so doesn't require any external attachments. Chips inside of a smartphone's built-in camera are sensitive to gamma rays; GammaPix uses its software to measure the impact of those rays, and give a picture of radioactivity in the area. The company says it works from up to 100 meters away.