Also forget to mention earlier about another App named "Zello"that has had much use in emergency operations after Hurricane Harvey and now Irma.

The walkie talkie app Zello , which played a major role in volunteer efforts in the aftermath of Hurricane Harvey, is being downloaded by millions as Hurricane Irma approaches South Florida.

Zello is used almost exactly like a walkie talkie, except it relies on wifi and cell service, so it can support big groups of people in dispersed locations. When Harvey caused widespread devastation in and around Houston, volunteers leaned on Zello to coordinate search and rescue efforts. And people in the path of Irma seem to believe they can put the app to similar uses in this storm too.

I downloaded it this morning and seems to have a lot of promise for both small and large groups.