[treetalker]

I use the free version of PDF Expert on all my Apple devices, and it's pretty great. (I use it for heavy-duty highlighting and annotation, document creation/merging, creation of tables of contents, as well as handling large pdfs — appellate case records, briefs, etc.) I'm especially fond of how it works on my enormous iPad Pro with the Apple Pencil: almost as good as, and in many ways better than, working with real paper and pencil.