This app displays the files contents available on your iPhone. You should note that you will not be able to create folder or edit file using this app. This app is specially designed for the developers. Using this app they can learn about the internal organization of the iPhone file system.
FileSystem app is compatible with iPhone, iPod touch, and iPad running iOS version 4.2 or later. It is 0.4 MB of size. FileSystem app is available worldwide exclusively through the App Store in the Utilities category for free of cost. You can download and get more information about FileSystem app from here [iTunes Link]