Coffee/snack purchase logger

Create an iOS application that can be used to log purchases of (typically) coffee and snack. The application needs to have: - A main screen with 3 input fields and 2 buttons (one for submit and one for clear) - A screen where the user can see all available items in the "store". The items are to be downloaded dynamically through an API I provide. - The user must be able to click a plus/minus-sign on each item to increase/decrease the amount of each item he wishes to purchase. - When the user has entered the items he wishes to purchase clicking a "return" button should take him back to the main screen where the fields should be filled with the purchase information he provided. - When the user clicks the submit-button data validation has to be done. - If this succeeds a confirmation dialog should be presented. - If the user clicks yes the information must be sent and stored in a database through an API that I provide. - If everything succeeds a "successful" dialog or similar should be presented. - Possibility to store a specific value of each field to be prefilled when the user starts the app I have a working Android-app with all this, I just need an iOS version with exactly the same functionality.