Combo of billing web app and complimenting PC side app is needed, where PC user (restaurant staff) should be able to register or login and should be able to input certain data. Database should be capable of exporting the same data via RESTful APIs to the PC and mobile clients. Entire database will be residing on Google Cloud Storage.
The web application would interact with PC based app (to be used by the restaurant staff) and a mobile app (to be used by the restaurant customer). PC user would input the details of the menus and other pages he wants to display on the mobile client. Mobile client will get the Menu and page details from the web app via REST APIs and display them appropriately for the customers who come to restaurants. Web app would be able to receive, store and respond to the data sent from the mobile and PC apps.
In addition to new features, PC user would get all the features what typical billing software provides. Henceforth, PC app will be called as PC user and the mobile app will be called as mobile client.
Experience in Google App engine, billing software and payment gateway integration is a must . Developers/companies who can perceive the overall product, suggest some new features and can do a critical analysis of the attached SRS need to reply.