Droid Explorer is described as 'A tool to manage your rooted Android device with the simplicity of Windows Explorer' and is a File Manager in the File Management category. There are more than 50 alternatives to Droid Explorer for a variety of platforms, including Android, Android Tablet, Windows, Mac and F-Droid. The best alternative is AirDroid, which is free. Other great apps like Droid Explorer are Amaze File Manager (Free, Open Source), Solid Explorer (Paid), MyPhoneExplorer (Free) and Simple File Manager (Free, Open Source).
X-plore is a file manager for mobile phones, with a wide range of functions on the phone's file system. NOTE: the free version has a 3sec wait screen at start and closing the app. So it is technically not 100% free but slightly 'nagware'-like.
ZArchiver - program to manage archives in android. The program has a simple and functional interface. It lets you create 7z (7zip), zip, bzip2 (bz2), gzip (gz), XZ, tar archives, decompress 7z (7zip), zip, rar, bzip2, gzip, XZ, iso, tar, arj.