PDFTK Builder - PDFTK Builder is a free graphical interface to for PDFTK, making it much easier to use.
ScanTailor - Scan Tailor is an interactive post-processing tool for scanned pages.
QPDF - QPDF is a command-line program that does structural, content-preserving transformations on PDF...
Briss - Cross-platform application for cropping PDF files in a simple and fast way via a GUI.
iSafePDF - iSafePDF is a free open source PDF protection software.
ScanKromsator - Scan Software with several advanced options