One UI is Samsung's latest design language and so far it has received a healthy number of positive reviews. Unlike the one size fits all saying, that isn't the case when it comes to software interfaces. Most of us will put up with certain UI elements but would much rather have the ability to change things. You may know of XDA Recognized Developer and Retired Forum Moderator Zacharee1 from his System UI Tuner application and now he has released a new application called the One UI Tuner.
Similarly to the System UI Tuner, the goal of One UI Tuner is to let you customize various UI elements that Samsung has laid out in their new software. The new application uses Samsung's comprehensive theme engine to add some functions that were removed with the update (examples include enabling seconds in the status bar clock or changing the Quick Settings header count using Android's hidden settings). One UI Tuner does not require root access nor do you need to execute any ADB commands either.
The developer does note that if you are prompted for root access then you're more than welcome to deny it. These prompts are put in place for future updates to allow the app to silently apply changes. But as of right now it currently has no effect.
The app costs $1 and is available from XDA Labs. The XDA forum thread linked below is where you'll find support for the app.
[appbox xda tk.zwander.oneuituner]