This extension adds checkboxes to the Github Pull Request 'Commits' view, making arbitrary commit diffing easier
Github's Pull Request tool defaults to compare the branch/fork base vs. the branch/fork HEAD. This can make 2nd and 3rd round reviews difficult, as the changes between revisions are not obvious. This plugin adds checkboxes to the "Commits" view, allowing you to diff arbitrary commits. This makes see what changed between PR revisions much easier. Now you can tell if the reviewee actually made the changes you suggested.