The Final Cartridge III Plus is a remake of the original Final Cartridge III with some extra features added, such as speeding up modern SD-Card solutions like SD2IEC and PI1541. 

Here are the main features:

1. GUI environment. Unless RUN/STOP key is held down during power-on or reset, the cartridge presents a graphical WIMP desktop.
2. Speed up disk and tape operations.
3. Provides an extension to the Commodore BASIC.
4. Freezer feature allows to save the memory contents to disk to be resumed at later point.
5. Works well with a SD2IEC-Floppy.