Native Youtube app suddenly stopped working on iPad 1

It's been some weeks now, whenever I try to used my Youtube app, it tells me it's impossible to connect to Youtube. Since it's an iPad 1, I have had trouble finding information online.

Did Google or Apple stop supporting the app? Is it finally obsolete? Is there another app I could use that works on iOS 5?

Just to be clear, I did not tinker with my device. I did not change its parameters, I did not jailbreak it, it connects to the Internet just fine and I've tried the app on different Internet connections. Also, this is not a login problem, the app just refuses to let me browse videos, whether I'm logged in or not.

Thanks for your help.