Video details: optional. A free YouTube API key fills in details (like length) for links you save without opening them. "How to get a key" explains it, in five minutes. The key is kept encrypted on this computer, shown only as its first and last few characters, and never put in a backup or an export: Replace or Remove it any time.
Comfort: Inbox reminder, larger text, reduce motion, stronger folder colour, and the theme (follow YouTube, dark or light).
Your Matinee: monthly counts of what you've used, kept on this computer only. Copy summary if you want to share them.
Export: your whole library as Markdown or CSV, in the layout you choose (see below).
Help & feedback: opens an email to us with only the version number filled in.
If your Chrome is too old for something, Settings says what and how to update.