Nice to have

Keep in mind the iPhones built-in microphone only goes up to 115dB. That said, this app is great to have around. Its cool to see how loud the ambient noise level is in your bedroom, office, movie theater, car, or train. It can be turned upside down so you can point the microphone where you want. Also, there is a resettable Peak Hold option now. Note: I would recommend changing the Sample Rate to about 3 seconds, as the default is much too fast to be really useful.

landbamirum about Decibel Meter