ServiceLocator Pattern for iOS

AppDelegate.m

- didFinishAppLaunch
{
  ServiceLocator* serviceLocator = [ServiceLocator new];
  SomeService* someService = [SomeService new];
  
  [serviceLocator useObject:someService asServiceForKind:[someService class]];
  
  SomeViewController* vc = [SomeViewController new];
  vc.serviceLocator = serviceLocator;
}

ServiceLocator.h

@interface ServiceLocator: NSObject

- (void)useObject:(id)object asServiceForKind:(Class)serviceClass;
- (id)serviceOfKind:(Class)serviceClass;

@end

SomeService.h

@interface SomeService: NSOject

- (void)doStuff;

@end

#import "ServiceLocator.h"

@interface ServiceLocator(SomeService)

@property (nonatomic, readonly) SomeService* someService;

@end

SomeService.m

@implementation SomeService

- (void)doStuff {};

@end

@implementation ServiceLocator(SomeService)

- (SomeService*)somService
{
  return [self serviceOfKind:[SomeService class]];
}

@end

SomeViewController.m

#import "SomeService.h"

- (void)viewDidLoad 
{
  [self.serviceLocator.someService doStuff];
}