Expert PDF Reader is a compact program for viewing PDF files.
There are no great surprises here. The program can display your PDF file in multiple ways, just as you'd expect. You can view a single page, two facing pages, or see the page full-screen, for instance. You can view the file's bookmarks, or navigate via thumbnails of each page. And there are all the usual options to rotate pages, zoom in and out, adjust page size, width and more.
It's just as easy to annotate your PDF files, though. Have you spotted a line or two of interest? Then highlight it with the Highlight tool. You can also draw lines on the page with the Pencil tool; insert a "Sticky Note" with a custom icon; attach a relevant file to a particular page; insert a Text Box where you can type your own text; insert a pre-designed stamp ("Draft", "Confidential", "Approved" and so on), and more.
But despite all these features, the program still remains lightweight, loading files quickly and allowing you to navigate them at speed.