Unfortunately, "a PDF" is not necessarily useful to anyone.
The format was fundamentally designed for print layout; in order to make a PDF, I have to dictate what size paper I'm laying out. The resulting document isn't flexible across differently sized or oriented screens; if I set the paper size larger or smaller than your display, or I set the font size smaller or larger than you'd like, you're just stuck with a PDF that's hard to read.
ePub isn't an Apple format? — it's a cross-platform ebook publishing industry standard, originally in competition with and now adopted by Amazon's Kindle. Ebook reading software for literally any platform should support it.
I should also point out that I am willing to meet people halfway on formats, but I'm not prepared to waste effort on a PDF for you that might just be unreadable — and you haven't told me anything about the screen you want to read it on.
