Apple Watch users have found that the device's built-in walkie talkie feature is a great boon for those who are out and about and don't want to bother with full calls. Samsung took notice of this, and added a WalkieTalkie app for its latest smartwatch. It's available to download now, but unfortunately it's only for its latest smartwatch.
While there's certainly a space for network-powered instant chatting, the utility of the Watch4's WalkieTalkie app is limited. Extremely limited at the moment: not only is it restricted to Samsung watches, it's only available on the Galaxy Watch4 and Watch4 classic. So if you happen to live in an all-Samsung house or work in an all-Samsung office, its ability to add contacts from your Samsung account and talk to them instantly is pretty cool. Otherwise, well, you're out of luck.
There's no phone component of the WalkieTalkie app beyond its connection with Samsung's proprietary Contacts. We might see it spread to more Samsung watches in the future, but don't hold your breath for it on anything else. The app is also on APK Mirror.