This is a plugin for Dolphin & Konqueror, which provides simple GUI actions to combine or alter PDF files. Dolphin & Konqueror are applicable to Linux only.
pdfForts does not appear to be packaged by many distributions. Obtain from https://github.com/sjau/pdfForts Note that the install.sh script appears to have been written for KDE4 and does not put files in the correct location for KFrameworks5. see http://www.makeuseof.com/tag/build-linux-productivity-machine-kde-service-menus/