No direct "download YouTube upd" exists outside the App Store’s legacy version system. Avoid third-party IPA sites – they often contain malware or require a jailbreak.
This creates a web clip that acts like an app. The mobile web version of YouTube is surprisingly lightweight compared to the app and is often more stable on older hardware. It also supports modern web standards better than the outdated API calls of the legacy app. youtube for iphone 4 ios 712 download upd