iOS: Force clock to be displayed at all times

Is there a way to make the iPhone always display the current time, even in full-screen apps? (Or maybe a way to at least force it to while in specified apps?) I understand why some people would want to forget what time it is and allow themselves to become absorbed in their game or video or whatever. I also understand why some developers might want people to forget about everything else and just continue using their app. "Engagement metrics are up! Hooray!" But there are times when I still need to keep an eye on the time, and... oops! And exiting to the home screen to check the time, only to find that you didn't need stop what you were doing because you've still got a few minutes - that's annoying too. That then leads to a reluctance to leave the app, and imprecisely guessing what time it is instead. Yes, the alarm feature is helpful for some cases, but not all. I'm not always trying to alert *everybody*. Sucks to be late a few minutes despite carrying a "clock" at all times, because sometimes it won't show the time.