Example of enabling background app refresh and updating the app icon badge number

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:UIApplicationBackgroundFetchIntervalMinimum];
    return YES;
}

- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    if ([[ItemManager new] reloadItemDataSynchronous]) {
        ItemHelper *helper = [ItemHelper new];
        NSArray *items = [helper getNewItems];
        if(items.count > 0){
            int newItemCount = [helper getNewItemCount];
            [UIApplication sharedApplication].applicationIconBadgeNumber = newItemCount;
        }
    }
    completionHandler(UIBackgroundFetchResultNewData);
}

Looks like this is not working on iOS 11, and some lower versions i think.

These type of background tasks just active whenever iOS feels like it. For most apps I've done you're lucky if you get called twice a day.

iOS 11 has a new API that lets you schedule real background network operations. https://developer.apple.com/documentation/foundation/url_loading_system/downloading_files_in_the_background?language=objc