The default unit for temperature for a Go Wireless Temp is °C.

Graphical Analysis GW app for Android
To change units, select Toggle Units from the overflow menu. Units will toggle between °C and °F (US-English only) or K (all other languages)

Go Wireless app for Android
To change units, tap the live temperature value displayed in the temperature meter. Alternatively, you can select Toggle units from the overflow menu. Units will toggle between °C and °F (US-English only) or K (all other languages)

Graphical Analysis GW app for iOS
You can not yet change units sensors with this software.

Go Wireless app for iOS
To change units, tap the live temperature value displayed in the temperature meter. Alternatively, go to the Settings app on your device (from the home screen). Choose GW Temp from the list of apps on the left to view or change the setting.

LabQuest app
To change units, tap the meter in the Meter view and select change units. You can change units between °C, °F or K.

Logger Pro 3
To change units, select Change Units from the Experiment menu, then choose your sensor and the desired units. You can change units between °C, °F or K.