In my most recent post, I shared different ways to give feedback in Google Docs using comments, automatic substitution, Kaizena, Google Keep, and screencasting. There is one extension that I had heard of but did not include it into that post. The last time that I had used the extension CheckMark, it had a default list of comments that could not be customized. However, the developer listened to user feedback and updated the extension so that users could add more comment labels and descriptions. This makes it an amazing tool to use to give feedback, and my recommendation would be to use this along with a screencast/Kaizena. See the video below for a brief run-down of this awesome extension!