They have removed the standalone app because it's not in built into iOS 12:
`The app allowed users to control their Apple TV using a simulated remote control on their iPhone or iPad. But now that the feature comes already built into iOS, we can see why the app seems a little obsolete and unnecessary.`
FWIW, I have an Apple TV Gen 3 from 2012 and an Apple Watch Series 5.
From dummies.com:
>Apple Watch Remote app
Not only can you remotely control your iPhone music via your Apple Watch, you can also use it to access a nearby Apple TV box connected to your TV. Your wrist-based remote can navigate the main menu, scroll through media lists, and select what you want.
I just looked at my watch and sure enough, there's the Remote app, never noticed nor used before (you can also download it directly to your watch via the App Store if you've deleted it previously.
I turned on my Apple TV, went to Settings/General/Remotes while wearing my watch, and darned if a 4-digit code didn't appear on my watch that the TV said to enter using my (vintage 2009) Apple Remote Control.
Instantly, my Watch synced to the TV, such that I can now use it in lieu of that elusive skinny remote.
- Too small -- easy to lose and hard to find.
- Too symmetrical. In the dark it's hard to figure out which way to orient the remote.
- Too sensitive. If I (or my cat) accidentally brush against the top surface, that's a button press.