WBFS Manager is described as 'This application basically provides a GUI for working with hard disk drives that have been formatted to the WBFS file system' and is an app in the File Management category. There are four alternatives to WBFS Manager for Linux, Mac and Windows. The best alternative is Witgui, which is free. Other great apps like WBFS Manager are Wii Backup Manager (Free), Wiithon (Free, Open Source) and jwbfs (Free, Open Source).
Witgui is a free Wii and GameCube game manager for macOS. It is a graphical user interface based on wit (http://wit.wiimm.de/wit), wwt (http://wit.wiimm.de/wwt) and the gametdb.com database. You will love its intuitiveness.