Developing an Android and IOS app -- 2

good afternoon I need an android app and ios for use within my restaurant I want an application where the User will see the menu (restaurant food and drinks) will choose your request and send the request to an admin panel (which had been in the kitchen) In the application the User can also view your order so made in the total amount that needs to be paid remembering that do not want to have the payment option within the app, only the User can view the value that will be your account Also have the option to call the waiter at your table since the administration panel, it must be possible to make a price change of food and drink, add new foods and drinks and add categories must have a system to track who is using the app, I thought of putting a qr code so that only the User who is sitting at the table can access the app, and I can revoke access when he leave the restaurant like a budget I await contact soon thank you