I see it in the Google Play Store in the US it probably has propagated out to all countries now.
actually have no idea what the companion app is…is it kind of android mobile app?
Actually Rev is not creating a companion app that is a mobile app that works with a wear app to complete the functionality. What he is creating is a bundled app that is an app with the same name as the watch. But watch sellers are calling them a companion app 
All the mobile app does when opened is tell the user how to download the watch face. It is said that this allows buyers to download the watch face before it has propagated to the store listings.
This thread is long but seems to have a lot of useful information
Ron
Samsung Developer Relations