I built a GitHub app that checks for uncompleted checkboxes within pull request comments and blocks the merge if found.

This allows you to treat checkboxes as to-do’s and:

* Open pull requests with a to-do list template -> make sure all steps are completed before merging

* Leave to-do reminders for yourself as you work on a pull request

* Leave to-do reminders for someone else as part of your code review

Especially useful for large PRs with collapsed comments.