Add or remove pages via the Page Management menu. Click Page Management on the left-hand menu to make the page management menu appear on the right-hand side of the page:
Click the add page button to add new pages, the trash icon to delete pages and the x to collapse the page management menu. You can also re-arrange pages by dragging/dropping them:
Click the hamburger icon in the top-right corner of any tile to move the tile to a different page. Page numbers that are listed in green are open for the tile to be moved to, where as red pages are full.