Default Lg g2 how to modify/make the screen brighter?

I remember on my gnex that there was a way to boost brightness above max factory settings... Does anyone know how to do this?

My g2 seems to be struggling in bright sunlight... Its just not that easy to see. I am currently on a 4.2 rom. When I recently flashed a 4.4 rom it seemed that the screen was brighter. Any ideas?