This is a cool idea! It wouldn't apply to people who want to search all the videos on a given channel for specific keywords (including those they haven't watched). I can see it being useful for folks trying to locate a specific video they remember watching in the past, though.

One consideration is that getting the user's watch history would likely require calls to the YouTube API. So that means I would have to make this a paid service in order to offset the code of those API requests. The beautiful thing about the current iteration is that it doesn't rely on YouTube's API at all. By scraping YouTube pages and leveraging a few NPM packages, I'm currently able to offer free and unrestricted access to it.

If enough people request that ability though, I'll consider incorporating it.

Thanks for checking out my project and for the great idea!

Sadly YouTube API doesn't allow you to retrieve user's history, so you need to scrape that aswell.

I created a exactly that project: https://github.com/victor141516/YourArch

If you're ambitious, I think a compelling rap genius style social media site could be built based on people commenting on specific segments of YouTube talks (and podcasts, whatever). Rap genius (now genius.com) seemed to be doing something really novel, but then....something happened. But I think the idea is rich with opportunity.

This project is doing a variation of it:

https://news.ycombinator.com/item?id=31527544

My vision of it would require some pretty strong UI skills, or maybe nowadays it's not so hard to accomplish impressive things.

That'd certainly be useful