Not understanding how apple watch companion app is installed

Question

I'm currently working on building an apple watch companion app for my application and there's a scenario that is a bit confusing to me.

Say a user downloads my iPhone app, but doesn't have a watch. The same user gets a watch a little later. How is the companion app installed? Once the watch is paired with the phone, does the iPhone app install the watch app on its own? Any links for documentation on how this works?

I've been looking all through the Apple Developer documentation and can't find this explained.

Answer 1

Watch apps are installed using the Watch application on the paired iPhone.

The user can select Automatically install watch apps , in which case all available watch apps would be installed when they pair their watch (or when an app containing a watch app is installed if the watch is already paired).

If automatic installation is not selected then the user has to install the app manually using the Watch iPhone app.

Once WatchOS6 is available users will also be able to install watch apps directly from the App Store on their watch.