OpenGL: create a flickering black/white screen in accordance with the refresh rate (mobile)

Question

I am trying to make an application where the screen should be flickering black and white. I have a 120hz android phone. I would like 2 frames black and then 1 frame white, 2 frames black and then 1 frame white etc. This would basically show 40 white flashes in one second, which is what I want to achieve.

How can I link my white/black drawings to the refresh rate?