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Full user review
"Great appp with advanced features for pdf manipulation"
e.g. You can add images to pdf (like your signature)
In Mac OS X we can use the embedded app Preview for pdf manipulation as you probably know
With Preview we can perform simple tasks (and not so) on pdf files that are usually enough for most users
But PDFpenPro is the best advanced complement for pdf file manipulation that I could find
and is not so heavy like other apps