When you review a submission you see the name/group members of the submitter, the current submission status, and all submitted files.
On this page you can download the submitted files. You can also upload files on your own if you want to send a file to the students.
When a file is deleted, either by you or a student, it is only flagged as being deleted. As an administrator you can still see and download all deleted files by pressing the Show deleted files button.
Fire can be extended by writing plugins that interact with the system. On this page the tar.gz plugin is used and it is, therefore, possible to browse and list the contents of .tar.gz files from within the Fire system. You can write plugins to handle any file format in any way you like.