The Zello messaging app focuses on voice over traditional text messages unlike the Skype and WhatsApp applications, while Zello uses a user interface that is closer to a walkie-talkie, and this type of application is called a "walkie talkie".
The Zello wireless app makes keeping in touch with individuals and groups of people very easy, and it is also useful to facilitate communication between children or the elderly who know how to use the phone properly.
You can create private channels so that the people you choose can access the messages, but there are also public channels that anyone can join, so just search for something public like weather, camping, or anything specific like the name of the place or city, to see if there are channels General Zilo to them.
And when your connection to the Zello channel is active you can lock your phone and keep hearing it when someone talks, which makes this especially useful during emergency situations, and the application works on Apple and Android devices.