I am really looking forward to seeing this feature and playing with this more when iOS 12 is released in September. I could get it now (Apple Developer Program) , but haven't got the time to play with this in depth.
This will show exactly how much you are on your device, by the clever name shows how much actual screentime you have had. I beleive Android does already have something like this available.
I am most interested to see how much actual screentime my kids have on their phones, when at home I do ensure they are not spending the whole days and evenings stuck on them, plus I will be able to set limits on them. Some of their friends I know are never off them, I can see from the stream of messages coming, it does surprise me how much time they are on Whatsapp or Snapchat etc.
I am always interested in your thoughts so if you have any comments or feedback then please feel free to add any comments, or you can mail me here.