Notability
Notability is a note taking and electronic notebook app that allows students to take notes, sketch ideas, annotate PDFs, mark-up photos, record voice, add audio comments and more. Students can type or hand write notes. This is not a cloud based app but there is an Auto Back-up feature (see below).
Resources:
How to back up Notability to Google Drive
From Publisher- http://www.gingerlabs.com/
Support and How to's- http://support.gingerlabs.com/hc/en-us