Although other apps have offered the ability to annotate or mark up PDFs, Easy Annotate is one of the few, if only, app that allows side by side editing of PDFs.
You can learn more about the app on the Easy Annotate web site and watch the video below.
The developer describes the app’s features as follows:
– Side-by-side Editing
– Linking PDFs
– Full Dropbox support
– Annotate (highlight, underline, cross-out, draw)
– Print, mail, export
– Easy to use interface
So, if you are interested in having the ability to view and annotate PDFs side by side, you should check out this app.
iPad Notebook 
Thanks for the review!
Do you have any tips or suggestions?
Please share them with us, so we can further improve our app.
Definitely worth looking at, and thanks for the review. I’m in the process of running an iPad pilot at the school I teach at. I have a special interest group set up, and I would be interested to have your input on advocating iPad usage in education.
http://sigtel.wikispaces.com/
D Richardson
UPDATE 1.7:
* Splitscreen in portrait mode
* Send linked PDFs with working links
* Option to add new empty PDFs for notes
* Resize the splitscreen (adjust the size of the two PDFs)
* One-page view in landscape (auto-resize a page to use fullscreen)
COMING SOON:
* Google Drive support
UPDATE 2.0:
* Greatly improved annotating menu
* Greatly improved settings menu
* Google Drive support
* WebDAV support
Ideas and suggestions are greatly appreciated!