* its FREESome parents may not be able to pay for the app. I dont want their child to cry because of that.* Starts quicklyWhen your child is crying, you dont want to spend 20seconds tapping on your phone, do you?* works in air plain modeIf you leave your phone or tablet next to your child, you probably dont want to crump your child with any radio signal* battery efficientThis is obvious goal. This app consume almost zero energy.*Lightweight and easy to useWe do highly recommend not putting the phone closer to the baby than necessary.