Checking for iOS update on app store

gistfile1.m

NSString *requestPath = [NSString stringWithFormat:@"http://itunes.apple.com/lookup?id=%@", @"528968746"];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:requestPath]];
    
AFJSONRequestOperation *operation = [[AFJSONRequestOperation alloc] initWithRequest:request];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSArray *results = [responseObject objectForKey:@"results"];
	if (results && [results isKindOfClass:[NSArray class]] && [results count] > 0) {
		NSString *resultVersion = [[results objectAtIndex:0] objectForKey:@"version"];
		NSString *installedVersion = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];
		if ([installedVersion compare:resultVersion options:NSNumericSearch] == NSOrderedAscending) {
			NSLog(@"Out of date. (%@). Update to %@", installedVersion, resultVersion);
		} else {
			NSLog(@"Up to date (%@)", resultVersion);
		}
	}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
	NSLog(@"%@", error);
}];
[operation start];