One of the things I really like about iOS and iPadOS is that a tiny colored dot manifests itself in the Status Bar when your handset’s camera or microphone activates. Not only is it a great way to be reminded that your hardware is being used in the background, but it also promotes privacy by ensuring you’re in the know whenever an app taps into your camera or microphone.
I can’t count on my own two hands the number of times I’ve witnessed someone who forgot their device’s flashlight on and failed to realize it either because they were out in the Sun or because the LED flash was being covered by something. Having said that, a similar Status Bar-centric indicator for the rear-facing LED flash could also benefit users.