NEW YORK (CNNMoney) -- Tech entrepreneur Tom Katis isn't exactly Mr. Silicon Valley. Before creating Voxer, an app that turns your smartphone into a multimedia walkie talkie, Katis served in the U.S. Army Special Forces.
His 2002 to 2003 stint in Afghanistan planted the seed that grew into Voxer.
"We were using classic push-to-talk radios. That's what you get trained in, so that's what everybody's been using for a long, long time," he says. "It turns out when there's a lot going on, and you need to coordinate with a lot of different units, it's really difficult. If I want to talk to you, I have to interrupt you."
Katis wanted a technology that would allow for multiple conversations: something that would integrate voice, images, text messages and other elements. Smartphones were the key. When he returned to the U.S., Katis started building his app, which was released in May 2011 on Apple's (AAPL, Fortune 500) iPhone and November 2011 on Google's (GOOG, Fortune 500) Android platform.
With the tap of a button you can launch a Voxer conversation, sending a message to a friend or a group. Recipients can either listen live or ignore the dispatch and save it for later. It's part phone, part text and part multimedia IM.
"I don't really call these things phone anymore," Katis says, holding up his smartphone. "They're really mobile computers. Your telephone app on there is just like any other app. I see these people using our app more than they use the telephone app. I see it replacing a lot of email."
Voxer started gaining traction this fall after the Android version launched, allowing iPhone and Android users to connect with one another. The application took off in the Midwest and the Middle East, and spread quickly through Brazil before many early tech adapters caught on.
Katis won't comment on the number of users Voxer has, but he says it's now adding more than 1 million every week. The company, which has 30 employees, is in the process of closing its first round of funding.
While Katis envisions the app helping out in the public safety and first-responder field, he also sees it as a basic communication app for all types of users, including business owners.
San Francisco based Liquor.com CEO Kit Codik says his team uses the service for meetings.
"We'll occasionally do group threads where we are using both the text and voice features to talk about specific topics, which I find extraordinarily helpful," says Codik says.
He also likes the ability to organize conversation topics by threads: "You can create a group and have a specific chat on something, which is nice." 
