After a period of months of testing, YouTube recently launched a new and formal update for its application on Android and iOS. With this update, radical changes were made to the overall application design.
The floating download button has been moved to the highlighted top bar in red only, along with the search button and the personal photo. The biggest change is the bottom bar. It still carries the same tabs as the previous one, with the “Account” tab renamed to “Library” From the last menu, you can switch to watch history, history, private videos, later tabulation, list of playlists, and the Offline video option.
This new bar will be on the screen while browsing and if you watch a video it will disappear. To access the account settings you will need to click this profile picture. Finally, the update is progressively accessible to all users. It seems to be on the server side and you prefer to download the latest version of the app on iOS here, on Android go here.