I got the idea from:
It have to be red and blue and have the sounds....but here is the small details that need to be in this app. sounds need to sound muffled to replicate how it would sound if you were in your car and a cop outside was trying to pull you over.
how you would use it:
at night while driving you have to be sitting in the back seat. place the phone up high near the rear window in sight of the rear view mirror. turn on the app. blue and red lights start to flash then the sounds of police sirens.