Nearly all apps have some form off settings menu that allow users to store regularly accessed information and customize the app to their own preferences. These settings can be anything from changing a password to personalizing the color scheme or any number of other tweaks and adjustments.
If you have a lot of data and access to a web server, it is often best to cache data from this source, as this will both save battery and speed up the application.
First and foremost, we should consider how these setting can save our user time. No one wants to have to enter all their details every time they order a sandwich, nor do they want to have to construct the same sandwich over and over. This leads to the question of how we represent a sandwich across the system and how order information is sent to and received by the vendor.
Whatever technology we employ to transfer order data, we can assume at some point in the process there will be a human being making the actual sandwich. A simple...