The whole family was in the car the other day, and my husband was reading puzzlers to my children. From the back row, my son kept asking my husband to speak louder. It was hard to hear with the air conditioner on.
As he continued reading, he was fooling around with my phone. All of a sudden, his voice came through the radio, like a microphone. My children loved it as my husband continued to provided a tour guide version of our drive.
I love it because I tell them to keep it down or stop hitting each other without yelling! As we pull into our driveway, I also announce to collect all their books, garbage, shoes, and anything else that they might leave in the car.
The app is called MicPro and you can find it on iTunes: iTunes - MicPro