YT Auto-Organizer от Truth Samurai

A Firefox and Chrome extension that organizes the new uploads from your YouTube
subscriptions into categories (News, Podcasts, Music, etc.).

There are two ways to use it:

• Manual (free, no API key) — import your subscriptions and put each channel
  into a category yourself.
• Automatic (Pro, optional) — add your own AI provider key (Claude,
  Google Gemini, or OpenAI) and the extension sorts every channel for
  you, and unlocks AI search.

It reads your subscription list once off the YouTube page, then pulls each
channel's new uploads through YouTube's public RSS feeds — no manual scrolling.
By default it shows only channels whose notification bell is set to "All".