You must manually download new IPAs and re-sideload every time YouTube breaks compatibility (roughly every 2–4 weeks).
A newer fork of uYouPlus that adds "Low Contrast Mode" and fixes for newer YouTube server-side updates. Core Features of Modded YouTube IPAs youtube ipa latest version
A long-standing favorite that integrates ad-blocking and video downloading. You must manually download new IPAs and re-sideload