There is no shortage of file managers for android, both free and paid
The popular Paid file managers are
- MiXplorer = Paid, no trial, plugins to add functionality
- Solid Explorer = 14 Day trial, during trial, you get ads (Root explorer, archiver, Chromecast, File categorization) + Local + FTP, LAN, sFTP, WebDav, NextCloud, etc…..
- File Commander = 7 Day Trial, during trial there are ads, FTP, LAN, cloud providers, etc…
Free and open source
- Material Files = Simple file manager, but well done in terms of design and good android development practices, Open source mostly written in kotlin (Github =>)
- Amaze File Manager = Simple material design file manager, written in both Java and Kotlin (Github =>)
- NextCloud Android client = Works with the self hosted Next Cloud (But so do unofficial managers) (Github =>)
Free but not open source
- File Manager by Xiaomi = Has network options (LAN, FTP)
- Google Files = Basic, supports Google Drive and OneDrive, google drive launches the drive app