Once you have connected your iPhone to the CarPlay stereo, the TomTom Go Navigation app icon appears in the list of available CarPlay apps. Tap on the icon to launch the app.
Alternatively, if you open the TomTom Go Navigation app on your iPhone and then connect it to the CarPlay stereo, the app will be shown immediately on the CarPlay screen.
IMPORTANT: The TomTom Go Navigation app does not yet support location search via the CarPlay screen. If you need to drive to a location that is not already saved in the app (e.g. your Home location) then you must search for that location and set it as your destination before connecting your iPhone.