To accompany iOS 12.1, Apple has updated the Apple TV Remote app for the Apple TV set-top box. The 2.2 upgrade includes, per Apple’s release notes, general performance and stability improvements.
The free app allows you to control your Apple TV with your iOS device, foregoing the necessity to use the Siri Remote device. You can control Apple’s set-top box with a swipe of your finger or use the keyboard to enter text. Plus, you can use the app along with the Siri Remote.