Skitch is great for marking up images and annotating documents, and it’s brought PDF reading and markup back from the dead. You’ll need to be an Evernote Premium subscriber to take advantage of PDF markup, but regular Skitch users can enjoy general enhancements and bug improvements. From iTunes:

Hey, here’s what’s new in this release
- PDF reading is back. Open a PDF in Skitch.
- Markup a PDF is back. Requires an Evernote Premium account.
- Web capture has been added back
- Improved crop mode
- Lots of bugs were crushed (no actual bugs were harmed)

Previously, Skitch added a crop function to their iOS app, and improved integration with Evernote for choosing a default notebook to save to.

Grab the latest update from the App Store.