How to do "git commit --amend" using GitHub For Mac
git-commit, github-for-mac
Solution
Looking at the release notes, that feature doesn't seem to be available (idem for GitHub for Windows).
You could add that to the list of issues for GitHub for Mac (ofr recording) and using the contact form (for action).
Jonas mentions in the comments that there is a pending request for that feature:
Issue 30: "git commit --amend" feature in github for mac
Problem
Is the "commit --amend" feature not included in GitHub For Mac?