फ्लैश प्लस
You can screen flashing various colors.
Night walk.Emergency call.Experiment light color .etc...
*Don't stare！because flashes quickly.
You can change the flashing cycle.[10msec~9999msec]
*Display capabilities vary by machine.
Also regards the free version.(Flash)
Tested xperia(SO-01B)
Tested SH-01E