So turns out you don't need to pay $2.99 in the store to lower the brightness of the screen beyond the stock capabilities, so you don't have to flash your partner in bed at night with a bright screen; nor burn the valuable life of your eyeballs by reading at night in pitch black environment.
Neither the need for jailbreaking your device, as the function is built in the ios system.
Turns out you can use a filter in the zoom function, to do that just for you.
It gets about 50% darker, works on iPhone, iPads, just about any apple operating system.
You can turn on/off the feature by triple clicking the home button.
read here how:
https://9to5mac.com/2016/03/18/how-t...out-jailbreak/