Updates to the popular GoodReader app for iPad include a number of PDF-friendly changes. GoodReader 2.8, from Good.iWare, offers a more book-like reading experience with double-page spreads and a horizontal page-turning feature.
Users can now rotate PDF pages and manually crop out page margins, fitting more text onto a screen and eliminating white space. Another useful update is pre-caching; subsequent pages are rendered while users are viewing a page, allowing for quicker page turns.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.