Annotatings facilitates the creation of graphical text annotations for your photographs, emails, Web pages, and any other document that accepts images.
Easily attach a small non-editable, non-selectable blurb of stylized, framed text to any of your rich text documents.
We use Annotatings for pretty much all of our product screenshots in the Mac App Store and our website - and that's a lot of annotated screenshots. (Except this one because it sort of annotates itself.)
Note: Now requires OS X 10.7 or later.