YouTube Transcript Distiller от Michael Ruck

One click. The important points, right where other viewers can see them.
Features:

AI-powered summary via Google Gemini (free API key required)
Posts directly into the YouTube comment field
Prompt fully customizable
Supports 11 languages: Arabic, Chinese, English, French, German, Hindi, Japanese, Korean, Portuguese, Russian, Spanish
UI adapts to your browser language automatically
Your API key stays in your browser — no tracking, no data collection

Requirements:
A free Google Gemini API key from aistudio.google.com/app/apikey