Darken Background

[BeeJ]

I used to have an app that had an effect called
Darken Background.
It was a one click effect that worked perfectly.

I cannot remember the name of the app or find it on my PC.

I looked at GIMP and saw no easy way to do this effect.
Does GIMP or some other easy to use app do this effect?
Is there a script for GIMP that does this?

I am not familiar with GIMP and only have NERO and Essentials to play
with but neither seem to have this one click effect.

I loaded GIMP and have explored it some.

I am not familiar with using graphics tools so be gentle.
Layers scare me.

I am loading images I took with my digital camera and need to apply
this effect: Darken Background.

Thanks!