Android 5.1.1 is considered a legacy OS and is no longer officially supported by the latest YouTube app.
Since modern users are likely looking for features that bridge the gap between old tech and new capabilities, here are several feature concepts tailored to these different interpretations: 🔊 5.1 Surround Sound Enhancement Features youtube 5.1.1
Running YouTube on original 2010 iPads is difficult because the pre-installed app no longer connects to Google’s servers. How to Get YouTube on The First Gen iPad (iOS 5.1.1) Android 5
The search results for "YouTube 5.1.1" reveal two distinct technical contexts: a legacy version of the YouTube mobile application and the challenge of running modern YouTube on devices stuck with the or Android 5.1.1 (Lollipop) operating systems. 1. Legacy Mobile App: YouTube 5.1.1 1. Legacy Mobile App: YouTube 5.1.1