QPDF is a C++ library and set of programs that inspect and manipulate the structure of PDF files. It can encrypt and linearize files, expose the internals of a PDF file, and do many other operations useful to end users and PDF developers.
a graphical user interface for the PDF Toolkit (PDFtk)
PDF Chain is a graphical user interface for the PDF Toolkit (PDFtk). The GUI supports all common features of the command line tool in a comfortable way.
...It is capable of selecting specific PDF pages or range of pages, which lets you have more control on the output file. Be able to produce compacted, smaller sized files in any operating system.
Its features makes it a great, must have, tool for everyone.