Download of KATANAFxFloorBoard 2020.05.03 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free Mac application is fxfloorboard. We recommend checking the downloaded files with any free antivirus. The application is included in Audio & Video Tools.
From the developer:
Fx FloorBoard is an application that helps you edit patches via midi on the BOSS Multi-Effects/AmpProcessor. The tool emulates the GT user interface in a graphical way so you can do realtime editing of settings from your desktop. It provides you with a patch text view of all your patch settings and allows you to print or save text list to file.
You may want to check out more software for Mac, such as V-Synth Librarian, SongScreen Liquid or VirtualDeckBrowser, which might be related to KATANAFxFloorBoard.