App idea: an app that let's you find any video by typing in a phrase

I know there are a few websites that already do that, but those sites are specifically for finding YouTube videos. The app I would want to make would be for finding videos from all websites. You could even narrow the search down by site, duration, and date.

Basically like Google advanced video search, except the "this exact word or phrase" part would apply to spoken words, not the words in the title, description, or comments section of videos.