Microsoft is planning to include a File Explorer app with Windows 10 Mobile, which replaces the current Files app available on Windows Phone 8.1. Not much differs from the two apps functionally, however the new File Explorer app includes a welcome new user-interface.
Starting off with its UI, the new app incorporates the hamburger menu, something new throughout all the apps on Windows 10. Clicking the hamburger icon opens up a list of storage places, as well as your most recent files. A device that has an SD Card will have that SD Card show up within the hamburger menu too.
It is now possible to move folders from one location to another, which was oddly not available in the Files app on Windows Phone 8.1. To move a folder, press and hold on a file and select move. You can also change the view of how files are presented, being either as an icon / thumbnail or list.