If you could show my friend your support, just go download his app. There's a free trial version which allows you to view 1 hour of video before you have to wait 10 minutes to view more, or you could also purchase the full version for $0.99USD. I can't even buy it or use it as I don't have a Windows Phone, but if I did, I'd have this for sure because sometimes the official YouTube app can be rather glitchy.
Check it out on the Windows Phone Store
Here are a few screen shots!