The Core Location framework contains the classes that enable applications to determine the device’s geographical location. No matter what type of iOS device is being used, the Core Location code you write does not change.
In addition to adding the Core Location framework to your target, you also have to import the framework’s header file into files that need to know about Core Location classes. Every framework has a header file that imports the header file of every class in that framework. This file is always the name of the framework suffixed with .h.
Open WhereamiViewController.h and import the Core Location header file at the top. Also, add an instance variable to hold a pointer to an instance of CLLocationManager – one of ...