Unfortunately, PDF support, as it currently stands, is fairly barebones. Aside from being able to view PDF documents, zoom, and turn pages, the app does not have any other features. Indeed, unlike ordinary ebooks, the PDF portion of the app does not support bookmarks, highlights or the ability to make notes.
The 3.3 update ties in nicely with yesterday's announcement from PDF software maker Foxit that Amazon had made an investment in the company. Although Kindle devices natively supported PDF documents since 2009, reading them has always been a little cumbersome. Hopefully, Amazon's investment is an indicator that better support is on its way.
The update also brings support for Android 4.0 (Ice Cream Sandwich) devices and customization options, including new margin and line spacing control.
Head on over to the Market to update or download the app: