
Files tab lists all the files that have been downloaded. For each file you can see the Category, which is
based on simple file extension filtering. You can tune the categories in Settings -> File types if you want.
Files tab is not only for recording the downloaded material but also for launching external applications.
When you configure external applications (called tools) in Settings. The tools will appear here
in the toolbar for convenient launching.

Configuring external applications for invocation is very easy through the Settings/Tools window.
Simply browse (or enter) the path for the binary, provide any name you like and input any additional arguments.
Typically on Windows invoking the application on the command line with /? parameter prints a list of available
parameters. On linux the same usually happens with --help parameters.
Keyboard shortcut is optional.
Click on any of the applicable file categories in order to associate the tool with those types of files and then click OK.
After this the tool appears in the Files toolbar for quick launching.