File Viewer is more than its name implies. Besides allowing you to open and view the contents of various types of files, this program also gives you access to detailed information about the files you import and lets you export the offered data to your local directories.
All you need to do is to drag-and-drop the file you wish to analyze and the program will immediately give you access to a complete report. You can then export the info to your local folders and save the icon of the imported file as an ICNS file.
It will also let you watch movies, play songs, and preview images. Unfortunately, it's not capable of playing or showing several popular formats, like MP3, SWF, MKV, GIF, FLAC or OGG.
This application comes as an alternative to using Finder's Get Info utility for revealing file details. However, it doesn't let you edit file attributes like Finder's tool. For example, you cannot alter the permission options of the imported files.
To summarize, I don't think it's worth installing this app when you already have a default tool that provides you with identical details. Plus, File Viewer doesn't work 100%.