I've found that using the normal backlight of my phone is sufficient for a flashlight. But waking the iPhone (before unlocking it) only keeps it lit for roughly 6 seconds and having to fully unlock it with a passcode takes too much time -- not to mention it requires looking at the phone.
I've always been a bit dumbfounded that flashlight apps exist for the iPhone (actually, not that they exist, but that people download them). The main reason is that whenever I need light, I need it quickly. Having to:
- wake my phone
- unlock it
- input a passcode
- locate and launch an app
takes way too much time. Another reason is that for the average dark situation, simply having the screen lit (even if it's not pure white) generally suffices.
Unfortunately, when waking the iPhone, it only remains awake for a few seconds before going dark again. However, if you slide the slider to unlock it (even if you are prompted to input a passcode), it stays lit for a whole minute before sleeping.
So I've found that the fastest and most convenient way to use the iPhone as a flashlight (albeit a simple one) is to:
- Click the 'sleep/wake' button
- Slide the slider
This is half the steps required if you were to use an app, not to mention they can be done super quickly and without looking at the screen. And on top of all of that, as a bonus the Lock Screen ignores any Auto-Brightness setting making it shine more brightly than if you were to proceed to the Home Screen.
I tested this, and it works as described. It's good if you need the lighting briefly. The obvious reason for the flashlight apps is that sometimes one needs the light for more than a minute. And sometimes they operate as tethering proxies. (That's a joke, folks.)]