Most, if not all SatNav apps (I have NavFree installed) will require access to calling and address books. How else do you navigate to a contact? Or call the person you are navigating to to say that "Waze has routed me cleverly and I'll be 20 mins early"..
Permissions for access to sd cards to read/write/delete, phone status (make calls), access network services (download data or premium in app purchases) and so on....
It's not quite so scary when you think about it for a few minutes..
Given a secure mount with a power supply, a smartphone can do as well as a "dedicated" SatNav device. They are just as at the mercy of poor satellite signal as each other. Providing a sat boost in car can help both. Such as this
Des. . .