An app is only as good as its website, and Jekyll makes sites easy to build and maintain.
GitHub gives a full DevOps platform that's free and easy to use. It's all in the same place my code is, meaning I have one less dashboard to sign in to.
gitignore allows me to easily update and refactor projects, knowing that I can easily keep my gitignore files up to date. Plus it makes it so much easier to reason why something is included.