More than 1 million people downloaded walkie-talkie app Zello in just a day as Hurricane Irma hit the Caribbean, and it's now topped Apple's app store chart in the U.S. People are using it to talk to ...

It looks like popular walkie-talkie app Voxer is about to get some competition in the mobile voice chat space. A new app called Zello is growing like crazy, too – in fact, it’s growing faster than ...