Hello Rhino,
the software to the FRDM-FXS-MULT2-B can be found in this link.
JozefKozon_1-1687161386422.png
JozefKozon_0-1687161296745.png
As Michael mentioned, unfortunately we do not have a software for Arduino, but perhaps some enthusiast have already created a software and shared it. The Kinetis boards, that are supported are in this link.
JozefKozon_2-1687161512283.png
With Best Regards,
Jozef