Delegate.h

@interface SomeClass : SomeControllerClass <JSTutorialDelegate>
// ...
@end

JSTutorial.m

@implementation JSTutorial
@synthesize title;
@synthesize body;
@synthesize delegate;

- (void)generateTutorial {
  // do something here?
  if ([[self delegate] respondsToSelector:@selector(tutorialDidFinish:)]) {
    [[self delegate] tutorialDidFinish:self];
  }
}

- (void)dealloc {
  [title release];
  [body release];
  [super dealloc];
}

@end

JSTutorial1.h

@interface JSTutorial: NSObject {
  NSString *title;
  NSString *body;
}

- (void)generateTutorial;

@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSString *body;

@end

JSTutorial2.h

@protocol JSTutorialDelegate;
@interface JSTutorial: NSObject {
  NSString *title;
  NSString *body;
  id <JSTutorialDelegate> delegate;
}

- (void)generateTutorial;

@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSString *body;
@property (nonatomic, assign) id <JSTutorialDelegate> delegate;

@end

@protocol JSTutorialDelegate <NSObject>
@optional
- (void)tutorialDidFinish:(JSTutorial *)tutorial;
@end