This app continues to be one of the most important reasons I own an iPhone. I use it every single night, and it continues to help me to stop snoring and get a good nights sleep. This app turns the phone into a precision piece of medical equipment, so it needs to be calibrated and tested. This app is not like Angry Birds, where it is very simple to learn and use within a couple minutes. It will take a couple of nights sleep to get to where it will work for your personal needs and environment. However, once it is set up the way you need, it is a lifesaver. The developer is friendly and responsive. Support this app by purchasing it!