In education, we hear a lot about Common Core, Close Reading, and other educational jargon that strongly hints at the importance of annotation in digital documents. Teachers have long used notebooks and post its for offline annotation, but how is this accomplished with digital documents.
Awhlie back NotablePDF came across my screen. They had several updates since that time, and its looking pretty solid. It allows you to highlight, add comments, and even insert text notes. A brand new feature is the ability to select text to paste in a comment or elsewhere.
Give the NotablePDF extension a try. It can connect to your GAFE Google Drive account so you can work directly from your PDF's in Drive. You can also set it to natively open PDF's, so everytime you click on a PDF link, NotablePDF will open.
Assuming you have already added the app and connected it to your Google Drive, this short video demonstrates the highlighting feature.