Why is Onyx better than a walkie-talkie or a phone?

Onyx incorporates some of the best features of both. 

It allows you to talk instantly with multiple people at once with a single push of a button like a walkie-talkie, without forcing you to use or unlock a screen to do so. Unlike walkie-talkies, Onyx has unlimited range (as long as your phone can connect to WiFi or a cellular data network), so you can talk to your team almost anywhere. You can also create as many groups as you need, unlike traditional walkie-talkies, which limit the number of channels you can have.