Thinking of buying Kindle Fire HD for school, is there a PDF markup app?

Looking at the Kindle Fire HD 7" but mainly 8.9" for textbooks and other books.
As a student I will also deal alot of PDFs, is there an app to add notes/highlight/markup PDFs on the Amazon app store?

I tried the store demo in Bestbuy, and I tried reading a PDF with the built in PDF reader and it seemed like I could not even select text out of the PDF, let alone annotate.

Thanks

Hi,

yes you can markup PDFs - I use ezPDFReader Pro which is great for viewing PDFs, highlighting, underlining, striking out text, adding notes etc.