I had a situation recently where I needed to take two single-page PDF files and merge them together into one two-page document.

I tried doing it using the Windows software Foxit PhantomPDF but I did not succeed in figuring out how to do it. Luckily, I use Linux for which I've known that there are some software programs to join PDF files and make other modifications. I just forgot the names of most of them.

So after a Google search, I found the software called Pdfshuffler. It's in the Ubuntu repositories and I installed it on my Linux Mint laptop by running apt-get install pdfshuffler.

That's all there was to it, and then I located the program in the Linux Mint Menu, ran it, and I saw the very simple interface. I didn't care. As long as this program would join my PDF files together, I didn't care if it had a fancy interface.

I just dragged my files right on to the window and it loaded them into PdfShuffler. Then I clicked a litle button to export the files I loaded as a single document. It couldn't be any simpler than that.

PdfShuffler is easy to use, free, and it gets the job done if you need to combine multiple PDFs into one PDF file.