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.…