The WinRT APIs allow devs to create powerful 3rd party tools, which includes file managers. We even saw one a while back which could easily be your daily file manager app on your Windows Phone device. Again, there are many who would rather prefer something from Microsoft’s own facilities.
Suggested: Why there is no file manager in Windows Phone, and when you can expect to see it
A file manager for the WP 8.1 has been extensively teased by the software major, and it might not be long before we see a release. In fact, reports suggest that the file manager might come as soon as this month, which is heartening to hear. As you can see from the screens, the app obviously comes with a design language that compliments the overall WP OS. It might feature custom theme support like the OS, but again we cannot say for certain as yet. The app will allow you to perform the usual activities you associate with a file manager – cut, copy, paste, etc. It might also feature OneDrive integration, which would be quite a welcome addition.
