Most likely the version of new product UltraFinder starts with major version 13 because of release year 2013. Well, we have Nov. 2012, but main release year will be next year. Same was done with UEStudio released first time 2005. First version has had as major version 05. This version numbering is common practice for many software products nowadays, perhaps to help users to identify how old their used software is and when purchased the license.
UltraFinder does not only support *.pdf and *.doc. It finds all files matching a pattern. Searching for text in files supports also all files containing text (*.txt, *.htm, *.csv, ...).
PDF is extra mentioned because text in PDF files are ususally compressed and therefore standard find text in files features fail on PDF files. PDF files must be decompressed in memory to be able to search for text in a PDF file. Of course if a PDF file contains just a scanned image of a text sheet, UltraFinder cannot find any text in such an image PDF.
Finding text in DOC files is also mentioned extra because *.doc files are binary files containing text in ANSI as well as in Unicode mixed with additional formatting options. Therefore *.doc files must be first interpreted (UF converts them temporarily to RTF) to be able to find and output text in a *.doc file.