Yep... we've finally released Version 1.0 of Tagnotate for OS X. It's free on the Mac App Store for the first month - 400+ downloads just yesterday! Ideal for annotating PDFs and, uniquely, tagging those annotations so that you can use tags to collect all your annotations across all your documents in a single place. We've even got a short video introduction:
It's actually easier to use than it is to write a review of it on the Mac App Store. Which is a crying shame because that's what I'd really like everyone to do. Please? Pretty please?