Just to be complete, here's an implementation of Singleton which might be used from Interface Builder. The difference is in actualAlloc method. As [super alloc] would still call [self allocWithZone:] – it wouldn't allocate the object. "_alloc" IS THE KEY. Otherwise the object wouldn't be allocated From http://stackoverflow.com/a/13591502/547214

IBSingleton.m

@interface      IBSingleton : NSObject + (instancetype) shared; @end
@implementation IBSingleton
+ (instancetype) shared		{  __strong static id _sharedInstance = nil;     static dispatch_once_t onlyOnce;
      dispatch_once(&onlyOnce, ^{   _sharedInstance = [[self _alloc] _init]; }); return _sharedInstance;
}
+ (id) allocWithZone:(NSZone*)z { return [self shared];              }
+ (id) alloc                    { return [self shared];              }
- (id) init                     { return  self;                      }
+ (id)_alloc                    { return [super allocWithZone:NULL]; }
- (id)_init                     { return [super init];               }

@end