PDF app for Windows

[dfay]

pyPDF2? if you’re comfortable with python scripting

What PDF tool can split a "two/four slides on one page" layout into individual slides?

I created this Alfred workflow to deal with splitting scanned books (2 pages across) to 1 book page = 1 PDF page. It’s built on a python library, PyPDF2, which could probably be used to do the kind of splits you need as well. Here’s the Stack Overflow post that I used to get started:

The SO post linked above has some other options, mostly Java based.