Hi Kris,
the SFCE editor should be in English by default. If this is not the case, you can switch it to English in the bottom part of the window:
0_1575363932278_sfc-editor-language.png
As for the manual, it is only in Czech at the moment: https://www.rexygen.com/doc/PDF/CZECH/SFCEditor_CZ.pdf
Copy-pasting the contents into Google translate might help.
In general, this tool generates the STT transition table and touts array for the ATMT or EATMT function blocks.
Hope this helps at least a bit.
Kind regards
Jaroslav