In https://github.com/technobuzz/WhereAreYou I used the CoreLocation and the MapKit. CoreLocation allows the device to figure out the geographical location.
In the view controller, I used the CLLocationManager class which controls the geographical capabilities for the device. Note that I had to add the CoreLocation framework to the project, and add the following to the header file to use it
Moreover, added the CLLocationManagerDelegate to the view controller.
As well, in the view controller i used the MapKit. The MapKit allows you to show a Map on the device. This too required that I had to add the MapKit framework to the project, and add the following to the header file to use it:
For the MapKit library, I made use of MKMapView class. as well as the MKMapViewDelegate
In the MKMapView class, there is a method didUpdateUserLocation which tells us that the users location was updated. In this method gets invoked within the view controller, I make it zoom in on the map as follows (with a 250x250 meter region):
In this example, a location on the map is indicated using MKAnnotation. I created a class that conforms to MKAnnotation.
Note: I also did their QuizApp.