I think its the platform that should give that option to the user be it android, iOS or what have you. You cannot trust individual apps developers and marketers

I think its the platform that should give that option to the user be it android, iOS or what have you. You cannot trust individual apps developers and marketers to actually mean "Turn Off Tracking" even though the label next to the button says exactly that. On Android turning off GPS is right there in the drop down menu. On iOS they would prefer for you to always have it on and hence the option is buried deep in the system settings, which is not as easily accessible as it is in Android.