SystemUI Tuner app,
Used it on my S8+ and found some useful tweaks. I've now got 10 quick toggle icons instead of the default max of 6, disabled the battery icon leaving only the percentage text, enabled the clock seconds display and couple other things.
Looks neat, looks like a custom ROM.
Think I'll go further and turn off the icons for bluetooth and alarm clock as they are always on anyway.
I’ve also installed the Helvicta font which someone posted a direct link to on reddit (It’s £1.19 on the Galaxy Apps store…) and now the font is a bit more nicer looking. A subtle change, but a welcome one nonetheless.