With the PDF-Analyzer you have an informationtool specially for PDF files.
For everyone who's working much with pdf files. Without starting large PDF applications you can see e.g. in the Explorer (context menu) directly all worth knowing of a marked pdf file. That reaches from the document informations over page layout and security-relevant things up to the file attributes! Additionally the program offers text extraction and text-analysis of the selected pdf files. Xml-export of the shown ttributes/properties... It's a two-way-tool... You can use it from the explorer contextmenu and "stand alone" as a "PDF Browser", too.
There's an extended pro-version with password-reset and much more available, too.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.