Previewed at WWDC, launching in the fall.
watchOS 5 Beta 2 Includes Functional Walkie-Talkie App
When you launch the Walkie-Talkie app after installing the second beta update, you'll be able to scroll through your contacts and choose a person to connect to. The person on the receiving end of your Walkie-Talkie message will hear their Apple Watch beep and then they'll see a screen that will allow them to approve a connection.
At the current time, it appears that you can only choose "always allow" when opting to enable a connection with a person.
Once a two-way connection is established, you simply press and hold down on the talk button to communicate, as does the person on the other end. Conversations, which we've been testing, are crisp and clear with excellent audio quality.
If your Apple Watch is on silent mode, Walkie-Talkie ignores it, so you're still going to hear Walkie-Talkie beeps and incoming conversations. The same is true for Do Not Disturb Mode and Theater Mode, but there is a Walkie-Talkie volume toggle accessible by turning the Digital Crown. With a push-to-talk connection turned on, you and the person you're connected to can chat at any time, with no additional approval options available.
You can have multiple Walkie-Talkie conversations going at once, with each conversation listed in the app.
While a Walkie-Talkie conversation is enabled with another person, both of you will see a yellow Walkie-Talkie icon at the top of the Apple Watch.
If you want to mute a Walkie-Talkie conversation so you can no longer be contacted, you can scroll up on the Walkie-Talkie app interface and toggle off the "Available" icon. When unavailable, if someone tries to speak to you, they'll see a message that you are unavailable, and you'll receive a notification.
If you want to resume your conversations with people, you can turn the toggle back to "Available" and everything will work as normal. Both people in the conversation need to have themselves set to "Available" in the Walkie-Talkie app for it to be fully functional.
Walkie-Talkie and the other watchOS 5 features will be limited to developers until watchOS 5 is released in the fall, as Apple does not provide betas of watchOS to the public.