Read PDF (book) partly on mac partly on iphone and ipad, tracking most recently read page
I believe iBooks will load up and view PDFs and if you are signed into iCloud on all devices the last read page should sync between devices.

I stand corrected this does not seem to work, grrrr... I thought I remembered it working, sorry. I have no other suggestions other than to try other PDF readers on the app store. You might also want to ask the hive mind at macintouch.com. It often has solutions for seemingly insurmountable problems.