There's a good reason – Free Digital Temperature Review

Exactly that, there's a good reason why it doesn't work the way you'd expect it to. I have an iPhone, and the iPhone is not equipped with a thermostat sensor on it. So how does the app get a reading? It requires your location so it can get the temperature from your local weather forecast. This app does NOT get real time temperature. And requires your current location in order to work. I would much rather have an accurate weather app than this one.
Review by Fionnros on Free Digital Temperature.