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.
WinBrowser - The first multi-column file manager for Windows! The elegance of the Macintosh for your PC
Filza File Manager - Explore files and folders with list view or grid view. View / edit files with powerful viewers.
Solid Explorer - Solid Explorer is a powerful Android file manager featuring access to most popular cloud storages, root access and easy extensibility.
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?