PDF Chain Flatpak Request

Project information: 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.

Name: PDF Chain
Homepage: pdfchain.sourceforge.io
License: GNU General Public License version 3.0 (GPLv3)
Upstream has been contacted: No

Done :slightly_smiling_face: