Searching for "youtube ios 1257" leads to:
In version 12.57, the video player still allowed background listening with certain workarounds (prior to the widespread server-side blocking of background audio). Additionally, the mini-player was simpler and less intrusive. install youtube ios 1257 exclusive
The only official exclusive features for YouTube on iOS come from YouTube Premium: Searching for "youtube ios 1257" leads to: In version 12
| Feature | How to get on iOS | |--------|-------------------| | No ads | YouTube Premium subscription | | Background play | YouTube Premium | | Download videos | YouTube Premium | | Picture-in-Picture (PiP) | Free (some regions) or Premium | | Enhanced 1080p | YouTube Premium | install youtube ios 1257 exclusive
No special build number is needed — just update to the latest YouTube from the App Store and subscribe if desired.