Objective-C to obtain quick and accurate location in iOS

QuickAndAccurateiOSLocation.m

// setup
- (void)viewDidLoad 
{
...
    self.locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    locationManager.distanceFilter = 250; 
    self.desiredLocationFreshness = 15.0; // desired freshness in s
    self.desiredLocationAccuracy = 100.0; // desired location accuracy in m
    self.improvementAccuracyToGiveUpOn = 30.0; // desired improvement in m
    self.timeToFindLocation = 30.0; // timeout to find location in s
    self.locationManager.delegate = self;
   /*
    * Start in code with
    *    self.locationTimer = [NSTimer scheduledTimerWithTimeInterval:self.timeToFindLocation 
    *                                  target:self 
    *                                  selector:@selector(stopUpdatingLocations) userInfo:nil repeats:NO];
    *    [locationManager startUpdatingLocation];
    *    stopped via [locationManager stopUpdatingLocation]; or timeout
    *
    */
 
...
}

// called when location is updated
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    NSDate* eventDate = newLocation.timestamp;
    NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
    if (abs(howRecent) > self.desiredLocationFreshness || newLocation.horizontalAccuracy < 0) {
        // This location is way too old or straight up inaccurate. Keep trying to get better. 
        if(self.userLocation==nil) {
            // Storing this anyway as the best location we have so far, unfortunately.
            self.locationRecent=NO;
            self.locationAccurate=NO;
            self.userLocation=newLocation;
        }
    }
    else if(newLocation.horizontalAccuracy > self.desiredLocationAccuracy && (oldLocation.horizontalAccuracy==0.0||( oldLocation.horizontalAccuracy-newLocation.horizontalAccuracy) > self.improvementAccuracyToGiveUpOn)) {
        // Still too inaccurate but we are improving by enough over time or it's our first try. Keep trying to get better.
        if((self.userLocation ==nil) || (newLocation.horizontalAccuracy < self.userLocation.horizontalAccuracy)) {
            // Storing this anyway as the best location we have so far, unfortunately.
            self.locationRecent=YES;
            self.locationAccurate = NO;
            self.userLocation=newLocation;
        }
    }
    else {
        // OK everyone-we either have  a great location or the location isn't total crap but we're not improving by enough over time. Time to call it quits. 
        [self.locationManager stopUpdatingLocation];
        self.locationRecent=YES;
        self.locationAccurate = YES;
        self.userLocation=newLocation;
        [self finalizeLocationSearch];
    }
}

Hi Corbett!

I am building a location based app in Swift 3. I am doing the things that you describe ablove, but for some reason it takes time to get the initial location fix on my phone, is there a way we can do this better? (like uber getting location instantly). Thanks in advance