A free app for Android, by BasicAirData.
The RTD software was created as a support tool for RC/FPV flying, and one of its most crucial applications is measuring outside air temperature. You can precisely determine the temperature from the resistance measurement using the RTD app. The measurement is made using the Callendar-Van Dusen equation, which is used in the industry to calculate the temperature from the resistance value. The software has been designed to be used with a PT/RTD sensor, but it can be used with any type of RTD, no matter what its brand or the resistance value at zero degrees Celsius. Try the app now for yourself.