Default App for searching through different tubesites?

Well as you know there are lots and lots different tubesites out there. one can find all kinds of apps that are for use with youtube.

I thought it would be great if there was an app that lets you choose the tubesites to search through (or add sites). well maybe a download of the results if possible.

Is there anything like that available? or. somebody who could do it? I'm sure that lots of people would like that too at least I would guess.

thanks for any tips.