It is very unsafe and lonely for a woman to go home at night. This is a smartphone case. There is a screen on the back of the phone case. When the phone case is connected to the phone, when listening to music, the screen of the phone case reflects the jumping light to the ground along with the frequency of the music, and the phone is connected to the navigation. The screen can be refracted to the ground for navigation. When a woman goes home alone, there is music accompanied by jumping lights, and navigation to the ground, which can alleviate the inner loneliness.