I don't have cell service where I hunt in the mountains in Central PA, so that is why there is a need for the GPS.
I have been going out west to Idaho and Colorado where there is no phone signal at all. I use Gaia GPS on my iphone. Down load the map before going and your good to go. Keep a charger pack with you for back-up power. Why would I want to carry an additional item? Plus a phone gives a bigger screen than any GPS I ever seen.
Todays cell phones do not need a signal to use their built-in GPS antenna.
