In this repository you find some more or less useful automator workflows/ apps for your daily life. Currently they run under OS X 10.9.
If you need to compare to PDFs you can do it for free with the command line tool diff-pdf. It gives you a comparison of each page with highlighting the differences.
Install it with:
brew install diff-pdf
After that you can use it with:
diff-pdf --view file1.pdf file2.pdf
But for people which fear the command line is the automator app diff-pdf.app
It asks for the first PDF file, and the second, too and opens the diff-pdf view.
As dependency it needs the diff-pdf executable under /usr/local/bin/diff-pdf.
As a use case it's good to compare a PDF made by Indesign with and without converted text to path. There is a nasty "feature" which do not convert numbering in text areas. These have to be converted before in text and then you can convert the text in pathes.