Who would have thought, Samsung's flagship device in 2017, the Galaxy S8, would be successful and could run the new One UI 7 operating system based on Android 15 complete with AI features such as Circle to Search, Galaxy AI and also the Now Bar. Imagine that the Samsung Galaxy S24 is still running the Beta, the Galaxy S8 has received it.
For your information, it is not an official update by Samsung. Instead, it is a type of Custom ROM developed by an independent developer. This ROM is said to be taken from a Samsung flagship device that supports One UI 7 – but it is not revealed whether it is based on the beta version on the S24 or the stable version on the S25.
This One UI 7 Custom ROM on the Galaxy S8 is seen to have fast and smooth animations as if on a new generation flagship device. In addition, the Now bar is seen to work well and the brand new interface of Samsung devices is also seen to be the same. Unfortunately, the original developer no longer wants to continue development and this ROM file now only exists and the version is re-uploaded.
If you want to use One UI 7 on your Galaxy S8, you can follow the guide on this XDA page. It should be noted that installing a custom ROM on a Samsung device carries higher risks than other Android devices. This custom version of One UI 7 is also confirmed to have many bugs.