Software to control backlight stays on, on certain apps??

[Torx]

using the phone on the road for music or gps mapping.. i'd like to keep the backlight on especially when connected to power..

is there any such apps?
i'd like to pick and choose what apps will keep the backlight on during use.

i would find it a pita to constantly revert changes in the backlight settings on every car trip.. ya know?