I back with Sumnotes - Summarize PDF Annotations . The interface is super easy to use for someone like me who is notputer geek. As a resident physician I do lengthy reading. First I split my PDF into small chapters then I begin highlighting PDFs using various highlight colors. I use drawboard PDF app on surface laptop to highlight PDF into various colors. Then I upload my highlighted PDF to sumnotes I think extracting highlighted makes it very easy to revise the lengthy in a short span of time. Extracting highlighted also gives a sharp memory recall as well. I tried windows app PDF-highlights-extractor to extract highlighted however the extraction was not precise and results were dismal. I then tried sumnotes website and I was blown away. It was able to extract from PDFs which were not in good quality such as scanned PDFs. Their online service allow user to extract based on highlight color which I haven't seen before. I can choose to just extract with yellow highlights and leave the blue highlights. Pretty cool!! The option to selectively choose which to extract have been helpful on some occasions. I look forward to acing my boards with this strategy. .