Learned how to use Apple UIBarButtons in left or right side of NavigationController
Learned how to use NotificationCenter for obersving reloading and updating existing data from one to another screen
Learned how to update TableView based on inserting elements in array
Learned how to use UIActivityViewController for sharing specific data from application
Learned how to use UIAlertController, both for entering elements in a array, and for simple notification to the user that some action is not allowed
NOTE: Reset restriction is set, as Poppup Alert, if shopping list is empty. The same restriction is set for the share button.
Author: Orhanko
Source: https://github.com/Orhanko/Simple-Shopping-List-App