https://github.com/pdfarranger/pdfarranger

PDF Arranger is a small python-gtk application, which helps the user to merge or split PDF documents and rotate, crop and rearrange their pages using an interactive and intuitive graphical interface. It is a front end for pikepdf.

PDF Arranger is a fork of Konstantinos Poulios’s PDF-Shuffler (see Savannah or Sourceforge). It’s a humble attempt to make the project a bit more active.