Topic: Which books are in the app

I've looked every where and can't find a source list of which books are in the base app. Is it just the main rulebooks? Is it all companion books too? Are third party books in? How about any adventure path traits/feats/spells/item add-ins?

Is the latest errata factored in? I'm asking so I know how much work I need to put into adding content (if any) to see if it's worth investing in the extras (dm stuff).