Hmm. Well, there is a youtube extension for chrome and probably an add-on for Firefox as well. Not sure about a standalone app – I don’t think so but someone could correct me if I’m wrong.

Why do you want this? Just curious. Youtube on a chromium-based browser with ad-blocker isntalled is pretty much the ultimate youtube experiecne, though there are a few things that I can only seem to do on my phone app, like answer polls and such, maybe. I guess it depends on how active you want to be with the youtube community.