For those who call southeast Texas home, an app called Zello was a literal lifesaver in the first few days of Hurricane Harvey.

"Zello, in this example, is the glue that's held together lots and lots of volunteers and people and rescuers," said CEO Bill Moore.

Moore teamed up with founder Alexey Gavrilov in 2011, and Zello was born in Austin.

Users simply sign into a channel and use their phones like a walkie-talkie.

"Voice demands attention so its a much more trustworthy, much more intimate type of communication," Moore added. "Everything has been anchored around this live voice."

Last week in Orange, Texas, Zello users helped evacuate a pregnant woman on the Cajun Navy's southeast Texas channel.

Zello became the volunteer group's tool of choice last year when horrible flooding hit Louisiana.

The group now has hundreds of members.

In the aftermath of Hurricane Harvey they took to social media to encourage people who needed help to reach out.

Moore and his staff stayed glued to the channels and the storm rolled on. He is very pleased at how it all played out.

"If you look at how few people lost their lives in Harvey for the size of the city and the scale of it, and certainly the volunteer efforts are a big part of that and certainly Zello had a contribution, and we're all proud to have a little part of that," Moore added.

You can learn more about Zello here.