Once you have Doctopus installed and mastered (okay you don't need to master it, but are at least familiar with it), then get ready to  move on to Goobric! Goobric is an extension that you can find in the Chrome Web Store and works hand in hand with Doctopus, written by Andrew Stillman. Basically, you can create your rubric in Google Spreadsheets and then attach it to your Doctupus assignments. Once you have graded and filled out the Goobric it populates your Doctopus spreadsheet with the scores and attaches it to the end of your students' assignments in their Drive. Amazing!