I built a clickable concept index for long YouTube coding tutorials

The problem

I watch a lot of long coding tutorials on YouTube — 2, 3, sometimes
4 hours. React, Node, full-stack builds.

The problem: I always need to go back and find a specific part.
"Where did he set up the auth context?" or "When did she configure
the middleware?" Every time, it's 5 minutes of scrubbing through
the progress bar trying to find the right moment.

YouTube chapters help sometimes, but they're broad
("Part 3: Backend") — not specific enough when you need
the exact moment a concept is introduced.

What I built

A tool that extracts the key concepts from a tutorial video and
shows them next to the player with timestamps.

Click any concept → the video jumps to that exact moment.

Think of it as a clickable table of contents for any long
YouTube tutorial, but at the concept level — not just chapters.

Example: for a 3-hour React tutorial, you'd see terms like
useEffect, auth context, protected routes, JWT,
middleware — each one clickable, each one jumping you
to where it's explained.

Try it

Here's a demo on a real tutorial: https://www.atlandex.app/v/NZKUirTtxcg

(Heads-up: the demo video shows an extension prototype; the web version is the stable way to try it: https://www.atlandex.app/speech/paste

I'd love honest feedback:

• Is this useful when you're working through long tutorials?
• Is the YouTube scrubbing bar good enough for you?
• What would make this more useful?

I'm a solo dev, so brutal honesty is welcome —
better to hear it now than after building more.