Found this one out of shear necessity and it does exactly what I needed at the moment. I had an eye test in the hospital where they put some stuff in my eyes to get my pupils completely dilated. which results in a temporary sensitivity to bright stuff all over the place. Sunlight being the obvious one but my external Acer monitor that presented a problem. I got it second hand for a small price because the previous owner did not treat the  screen settings buttons all that well. Apart from that.. adjusting the brightness on the screen itself is always way to much of an effort.

A problem which got solved by this awesomely simplistic app! Just a slider which can be opened from the top-bar which dims everything except for the mouse cursor.. which I find quite a nifty detail ^_^