Use the Safari Web Browser . Navigate to youtube.com . While not as smooth as a native app, the mobile web version is updated by Google and will actually allow you to log in and watch videos. You can tap the "Share" button in Safari and select "Add to Home Screen" to create an icon that looks and feels like an app.
It is crucial to set expectations. While you will be able to watch videos, the experience will not be perfect: Youtube Ipa For Ios 5.1.1
Jailbreak with redsn0w 0.9.15b3 . Select “Install Cydia.” Use the Safari Web Browser