I upgraded my PC and foolishly thought I knew all the add-ons that I used so wouldn't need to write them down!
Basically I had an add-on that I thought was called something like 'lights out' or similar.
All it did was enable you to have a little button which changed the CSS of websites with the click of a button, so that white backgrounds became grey and made the whole page dimmer.
It had various different built in themes to choose from, and there was an option called 'stay in the dark' which meant whatever page was loaded in the tab you were in would continue to use one of the anti-glare/brightness themes for night time reading etc.
It was a great little add on, but I can't seem to find it anywhere. The icon was a simple little light bulb with a drop down menu to select different themes.
Can anyone help me find the add on please!?