AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  
  #if defined( DEBUG )
        [self dumpNotifications];
#endif
  
  
    return YES;
}
  

- (void)dumpNotifications {
    #define Debugger()    { kill( getpid(), SIGINT ) ; }
    NSNotificationCenter *notifyCenter = [NSNotificationCenter defaultCenter];
    NSArray *ignoreList = @[@"_",
                            // ???
                            @"com.apple.pasteboard",
                            @"AXFrontBoard",
                            @"FABSettingsAvailableNotification",
                            @"kGTMSession",
                            // UIKit
                            @"NSBundle",
                            @"UIApplication",
                            @"UIDevice",
                            @"UIWindow",
                            @"UIView",
                            @"UIText",
                            @"UIStatusBar",
                            @"UIKeyboard",
                            @"UINavigationController",
                            // user defaults
                            @"NSUserDefaults",
                            // rendering?
                            @"BufferBacking",
                            @"PBDefault",
                            @"com.urbanairship",
                            @"CTRadioAccess",
                            // core data
                            @"NSPersistentStore",
                            @"NSObjectsChangedInManagingContextNotification",
                            @"NSManagingContext",
                            @"NSManagedObject",
                            @"NSSQL",
                            // Flurry?
                            @"FIRAScreen",
                            @"Flurry",
                            // GCD
                            @"NSThread"];
    [notifyCenter addObserverForName:nil
                              object:nil
                               queue:nil
                          usingBlock:^(NSNotification *notification){
                              NSString *name = [notification name];
                              for (NSString *item in ignoreList) {
                                  if ([name hasPrefix:item]) {
                                      return;
                                  }
                              }
                              
//                              if ([name isEqualToString:@"NSThreadWillExitNotification"]) {
//                                  Debugger()
//                              }
                              
                              // Explore notification
                              NSLog(@"Notification found with:"
                                    "\r\n     name:     %@"
                                    "\r\n     object:   %@"
                                    "\r\n     userInfo: %@",
                                    [notification name],
                                    [notification object],
                                    [notification userInfo]);
                          }];
}

Learn what notifications your app is really seeing by dumping all of them to the console!

This code has a configurable ignore list that you can easily customize to see as little or as much as you want. I'm certain you will learn about notifications that you never even knew existed to make better apps, like UIScreenBrightnessDidChangeNotification.