Emergency Radio covers over 900 local areas, letting you use your iPhone to tune in to police, fire, and emergency services frequencies via Wi-Fi or your data connection. The popular app is one of the top paid apps (99 cents) in the iTunes App Store. It takes advantage of ability to identify your location, making it easy for you to search for nearby frequencies based on your current location. You can also search for specific cities/counties. The application also offers a customizable favorites list, and a list of scanner codes to aid in listening. You can find a list of the communities covered by clicking here. If you don’t see yours listed, you can request it. A free Lite version covers specific services in Chicago, Denver, Miami, New Orleans, and San Jose.
Also availble is Police Scanner ($2.99), which lets you listen in on police, fire, and EMS activities across the country. It has over 1,100 EMS streams, more than Emergency Radio, but the reviews don’t seem to be as strong.