A free program for Android, by Fresh Blood Software.

File Manager – File Explorer is an easy-to-use, modern app that lets you manage all of your files on your Android device, including the internal storage, the SD card, and any other external storage device, such as a USB flash drive. It’s a fast, lightweight, and highly customizable app that lets you manage your files and folders, copy, move, delete, rename, and share them between Android devices and other operating systems.

You can also browse your device’s storage devices, including the internal storage and SD card, and manage them as a single unit. You can create new folders, rename folders, delete them, or move them to the trash.