digital walkie-talkie

Generic name for the software that powers an app which relies on cell phone data plans or WiFi, it's designed to operate in places where signals are weak, such as after a hurricane, in order to help volunteer groups coordinate search-and-rescue efforts.

Historical perspective: In the aftermath of Hurricane Harvey in 2017, a “digital walkie-talkie” named Zello became the go-to app for rescuers working to save thousands of people trapped by floodwaters, according to The Washington Post. Volunteers monitoring social media used Zello to feed information to rescue boats patrolling flooded neighborhoods. As Hurricane Irma bore down on Florida shortly thereafter, Zello surged to the top download spots on Google Play and the Apple App Store. The app has 100,000 users worldwide, and is particularly popular with Hong Kong taxi drivers, as well as people in countries like Egypt and Venezuela where government services struggle to meet demand.