Z10 Lower Brightness

Hey everybody,
So I was at a play the other day and wanting to check the time on my Z10, I realised that even when the brightness was at its minimum, it was still too bright. Whereas all my friends on their other phones (even old BlackBerrys) could put their brightness really low.

I was wondering if there is a way to lower the brightness even lower than when it is at its minimum on the phone; like maybe a third-party app or something.

Thanks a lot !