1. Default view is magazine mode, which allows you to view 2-page spreads.
2. Hovering over a page's outside edge shows the next page arrow, and last page arrow.
3. The top center of the UI shows the prev/next arrows, flanking a thumbnail gallery view icon. The input to the right shows [current page / total page] field so you can jump to a specific page. The thumbnails at the bottom use a fish eye lens effect like the Mac OS X dock, to allow you to jump to different pages.
4. The thumbnail gallery view of pages opens in a lightbox.
5. Paper View mode showing the page navigator in the left. Paper view mode allows you to scroll vertically through the whole document.