For users holding onto vintage Apple hardware like the iPad 1 or the iPhone 3GS, the "YouTube IPA for iOS 5.1.1" is the holy grail of software. Finding a working version of YouTube for these legacy devices is a challenge, as the official app store stopped supporting iOS 5.1.1 years ago.
You can find archived versions like YouTube v1.3.0.5707 or YouTube 1.0 IPA on platforms like Internet Archive . youtube ipa for ios 511