Use the Apple Watch as a Walkie Talkie
Once you install the watchOS 5 update on your Apple Watch you can use it as a walkie talkie.
The new Walkie Talkie app on the Apple Watch allows you to use the new app to send audio messages that automatically play when you are marked as available.
This allows you to quickly chat back and forth with friends during the day or connect with them when you are at an event like a concert easily.
The other people you want to use this with need an Apple Watch and need to install watchOS 5.