nsmutablearray leaking the memory iphone
===

I have an nsmutablearray which i need through out the application so i declared it in application delegate and release it in dealloc method of application delegate. Here is the code for that. 

    @interface AppDelegate : UIResponder <UIApplicationDelegate>{
        NSMutableArray *arr1;
        IBOutlet UINavigationController *navConroller;
    }
    @property (strong, nonatomic) IBOutlet UIWindow *window;
    @property (nonatomic, retain) UINavigationController *navConroller;
    @property (nonatomic, retain) NSMutableArray *arr1;


    @implementation AppDelegate
    @synthesize navConroller;
    @synthesize window = _window;
    @synthesize arr1;

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
        self.arr1 = [[NSMutableArray alloc] init];
        [self.window addSubview:navConroller.view];
        [self.window makeKeyAndVisible];
        return YES;
    }

    - (void)dealloc
    {
        [self.arr1 release];
        [_window release];
    
        [super dealloc];
    }

when i check memory performance tool it shows me memory leak at

    self.arr1 = [[NSMutableArray alloc] init];

I am using this array in different classes. Any suggestion will be appreciated.
