In addition to the fitting module the WebFfit package has also a report writing module that is used by the fitting module to produce fitting reports in a quick way.
The Report Writing module is nevertheless independent of the fitting module and can be used to write more elaborated documents with the possibility to include (upload) figures other than those produced by the fitting module.
Report Writing uses LATEX(actually PDFLATEX) to produce the PDF documents. The document class is by default RevTeX.