But no app can tell you exactly what the temperature is right where you stand. That’s why Robocat, the developers of Haze and other smartphone weather apps, created Thermodo, a small device that plugs into the headphone jack of your Android or iPhone. Thanks to a highly-sensitive sensor inside of its minuscule housing, Thermodo can tell you the exact air temperature wherever you are, whether that’s at the top of a ski slope or sweating away in the sauna afterwards. It works with an accompanying app to show instant readings and if the temperature is climbing or falling.