Files - Keep everything organized without breaking your flow. Dropbox brings your files together, in one central place. They're easy to find and safely synced across all your devices—so you can access them anytime, anywhere.
Documents by Readdle - A central hub for all your files.
Filza File Manager - Explore files and folders with list view or grid view. View / edit files with powerful viewers.
FE File Explorer - The one-stop files solution
FileApp - FileApp is an iPhone and iPad File System and Document Viewer.
Files-finder edition - If you have to name one app which you miss most on your iPad, what would that be?