One of the functions iOS 7 which has not been talked about yet, is related to the Mail application and the possibility to open a set of files that were inaccessible until this version of the operating system. I'm talking about the .zip archives sent as attachments to emails, the Mail application from iOS 6, or smaller, being unable to access them if there is no application installed in our iDevice that knows how to read them. This changes to iOS 7, Apple implementing directly in its iOS a system for unarchiving these files, so you can open them without problems and you will probably also be able to open other types of archives.
This function is natively available on all Apple iDevices, so you don't need to activate it from somewhere.
