YouTube ReVanced is a modded YouTube client with features like no ads (partly broken in this version), background play and even features like SponsorBlock and Return YouTube Dislike (Return YouTube Dislike is broken in all ReVanced patch versions below 2.100) this is YouTube version 17.29 (the final version without "Update available") spoofed to 19.17.01 to fix "There was a problem with the server [400]".