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.
Opening a file within the File Explorer works liked expected. If a file you're trying to open is not recognized by the operating system, you'll be asked to search the Windows Phone Store for an app which is compatible with said file.
You can select multiple files and copy them, move them, or delete them, much like you would expect to be able to do in a file explorer. Furthermore, there's now an "Up" button included within the app, something many desktop fans will rejoice over.
The new File Explorer app can also act as a file-picker. You can choose it to navigate through your files if you wish to upload something via an app. There is no way to access the internal file system, meaning no true C:\ access to folders like Windows. This is to be expected however.
Microsoft is expected to continue to update the File Explorer app throughout the upcoming Windows 10 Mobile Technical Preview, so hopefully we may see a few more features get added to the mix before RTM.Further reading: Microsoft, Windows 10