File Manager for Windows Phone 8.1 Official has been released by Microsoft.
Here it is:
http://www.windowsphone.com/en-us/store/app/files/762e837f-461d-4847-8399-3526f54fc25e
Review:
http://www.wpcentral.com/hands-on-files-windows-phone-81
Here it is:
http://www.windowsphone.com/en-us/store/app/files/762e837f-461d-4847-8399-3526f54fc25e
Review:
http://www.wpcentral.com/hands-on-files-windows-phone-81