With iOS >= 10, you can show notification banner when app run foreground. To make it, you can add some line code in AppDelegate.m

//Called when a notification is delivered to a foreground app.
-(void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^{)(UNNotificationPresentationOptions} options))completionHandler
{
completionHandler(UNAuthorizationOptionSound | UNAuthorizationOptionAlert | UNAuthorizationOptionBadge);
}

Don't forget, import UserNotification in head:

import

Hope it work with you.