YouTube version 11.45.55 is the latest update to the video sharing platform and the update should be starting to roll out to users, and if it hasn't already it should be soon. That said, you can grab the APK file from the button down below if you don't feel like waiting on the update. As for what's new, the only thing that looks to be changed with this version is the round icon for the app, as well as app shortcuts, if you're on a device that isn't a Pixel which already had these things available with YouTube. Since the round icons and app shortcuts are only present in Android 7.1 Nougat, only devices which have this version of Android software are going to see these changes to the app if they weren't already there.
This version of YouTube isn't so much about new changes that are here as it is about features that are on their way. A breakdown of the APK file points to the inclusion of rotten tomatoes ratings for movies and such that are rented or viewed through YouTube. There's no indication of exactly when Google plans to add this in, but it might not be too far off. Another thing to look out for will be the quick seeking feature.
Quick seeking might be better described as fast forward and rewind, and if you've watched movies or TV shows through Play Movies before then you should already be familiar with the quick seeking feature as it's already implemented in that app. While you can already drag your finger on the slider bar to move forward and backward on videos, the quick seeking will be a much more accurate way of getting back to a particular spot. In addition to quick seeking, there are references to a couple of other features that are on their way at some point, including a video filter called Dance Party. There's no clear description of what this may be yet, but it was mentioned in the code. It looks like the YouTube app will also be getting just a little bit closer to adding the live broadcasting feature, and with it there may be an option to enable the LED light on the back to allow for better lighting during live broadcasts when there isn't enough light from other sources around. This could come in handy in a variety of situations as there isn't always going to be enough light during a recording. Lastly, there are going to be some new bitrate management tools.