Daily iPhone App: Zello lets you chat walkie-talkie style with friends, co-workers

After years of living in an area with no cell service -- but with a very active radio tower -- I grew accustomed to talking with my husband using a ham radio instead of text messaging. Now that cell coverage has improved, we no longer use our ham radios and have switched to the iPhone. To recapture that walkie-talkie style of communication, we recently started using the Zello+ Walkie Talkie app.

Zello+ is an instant, Nextel-style push to talk communication app that uses your mobile broadband connection to exchange short audio messages. The app lets you talk one-on-one to a single person or in a channel with a group of people. It requires a Zello account that is available for free.

After you set up your account in the Zello app, you can add Zello contacts and start talking. The app has a large red button in the center of the screen that is very easy to locate and press. You don't even have to look at your phone, as the button is the dominant element in the app.

Like most walkie-talkies, there is an alert function that lets you "ring" a person before you start talking. This feature is helpful when you want to talk to someone, and you don't know where they are. You wouldn't want your message to broadcast out loud during an important business meeting, for example. The alert uses the iOS notification system to let the person know that you want to talk to them.

Zello has a few useful features that set it apart from its competition. The app stores your most recent conversation so you can re-listen to a message that you missed or forgot about. It works with a headset, your phone's built-in speaker or a wired mic. It also works great over 4G, 3G, and GPRS/EDGE. I haven't measured it directly, but I can say that in all my usage, Zello contributes very little to my overall data consumption.

The Zello+ app is free and is meant for consumers. It's cross platform and works on an iPhone, Android device, BlackBerry phone or PC. If you are a business owner and want to use the system with your employees, Zello offers an @work service that is free for up to five employees. Pricing starts at $10 per month per user for businesses with more than five employees. The @work option provides a web-based management tool, encrypted messages and more.