When the user clicks (touch up inside) the “Take Photo” button, we have to create an UIImagePickerController and set its delegate to our AppViewController class. Also, we have to specify which kind of image picker we want to show, the camera with UIImagePickerControllerSourceTypeCamera, or a photo library with UIImagePickerControllerSourceTypePhotoLibrary; in this case we select the Camera. Once the picker has been crated, we have to present it modally with the method presentViewController.