Open source alternative to MapKit

#import "MapBox.h"
@implementation MyViewController
- (void)viewDidLoad
{
[super viewDidLoad];
RMMapBoxSource *tileSource = [[RMMapBoxSource alloc] initWithMapID:@"examples.map-z2effxa8"];
RMMapView *mapView = [[RMMapView alloc] initWithFrame:self.view.bounds andTilesource:tileSource];
[self.view addSubview:mapView];
}
@end