Blizzard
Hello.
Yes, the companion app is currently unavailable today (Wednesday, October 14).
Simply put, we had a bug with the new version of the app that goes with the Shadowlands pre-patch, and we’re releasing an updated and fixed version soon.
The fixed version may be available in your device’s store before we’ve had a chance to do the WoW realm restarts that are required for it to all work.
After you’ve gotten the app update, and we’ve done realm restarts in this region, it should work as expected.