// Add map view
//
self.mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
self.mapView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self.mapView setRegion:MKCoordinateRegionMake(CLLocationCoordinate2DMake(37.786996, -97.440100), MKCoordinateSpanMake(30.03863, 30.03863)) animated:YES];
[self.view addSubview:self.mapView];

// Create clusterer, assign a map view and delegate (MKMapViewDelegate)
//
self.clusterer = [[REMarkerClusterer alloc] initWithMapView:self.mapView delegate:self];

// Set smaller grid size for an iPad
//
self.clusterer.gridSize = UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone ? 25 : 20;
self.clusterer.clusterTitle = @"%i items";

// Populate with sample data
//
NSDictionary *data = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Points" ofType:@"plist"]];

[data[@"Points"] enumerateObjectsUsingBlock:^(NSDictionary *dictionary, NSUInteger idx, BOOL *stop) {
    REMarker *marker = [[REMarker alloc] init];
    marker.markerId = [dictionary[@"id"] integerValue];
    marker.coordinate = CLLocationCoordinate2DMake([dictionary[@"latitude"] floatValue], [dictionary[@"longitude"] floatValue]);
    marker.title = [NSString stringWithFormat:@"One item <id: %i>", idx];
    marker.userInfo = @{ @"index": @(idx) };
    [self.clusterer addMarker:marker];
}];

// Create clusters (without animations on view load)
//
[self.clusterer clusterize:NO];

// Zoom to show all clusters/markers on the map
//
[self.clusterer zoomToAnnotationsBounds:self.clusterer.markers];