NSURL *URL = [NSURL URLWithString:@"http://date.jsontest.com"];
NSURLRequest *request = [NSURLRequest requestWithURL:URL];
[ISHTTPOperation sendRequest:request handler:^(NSHTTPURLResponse *response, id object, NSError *error) {
    if (error) {
        return;
    }
    // completion
}];

[[ISHTTPOperationQueue defaultQueue] cancelAllOperations];

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"request.HTTPMethod MATCHES %@", @"GET"];
[[ISHTTPOperationQueue defaultQueue] cancelOperationsUsingPredicate:predicate];

[[ISHTTPOperationQueue defaultQueue] cancelOperationsWithHTTPMethod:@"GET"];
[[ISHTTPOperationQueue defaultQueue] cancelOperationsWithHost:@"example.com"];
[[ISHTTPOperationQueue defaultQueue] cancelOperationsWithPath:@"/foo"];

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    NSOperationQueue *queue = [NSOperationQueue defaultHTTPQueue];
    [queue addObserver:self forKeyPath:@"operationCount" options:0 context:NULL];

    ...
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"operationCount"]) {
        UIApplication *application = [UIApplication sharedApplication];
        NSOperationQueue *queue = [NSOperationQueue defaultHTTPQueue];
        application.networkActivityIndicatorVisible = [queue operationCount] ? YES : NO;
    } else {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

- (id)processData:(NSData *)data
{
    NSError *error = nil;
    id object = [NSJSONSerialization JSONObjectWithData:data
                                                options:NSJSONReadingAllowFragments
                                                  error:&error];
    if (error) {
        NSLog(@"JSON error: %@", error);
    }
    return object;
}