Kliky
Remote control for Apple TV
Apple TV 4K and Apple TV HD run tvOS and accept a phone as a remote on the same network. The first time you connect, the Apple TV shows a code on screen to confirm it is you.
Kliky gives you a touch surface for swiping through the Home screen, Menu/Back, TV, Play/Pause and volume, plus a keyboard for searches and passwords.
Apple TV remote for Android
Apple’s own remote lives in Control Center on iPhone and iPad and does not exist on Android. Kliky is the same app on both, so an Android phone in the household can control the Apple TV too, next to the Roku or Samsung in other rooms.
Siri Remote not working
Charge it for 30 minutes first; a drained Siri Remote gives no sign of life. Then restart it: hold the TV button and Volume Down together for about 5 seconds, until the light on the Apple TV goes off and on. To pair it again, hold Back (or Menu) and Volume Up for 5 seconds close to the Apple TV. Details are in Apple TV remote not working.
Lost Apple TV remote
An Apple TV that is on your Wi‑Fi can be controlled from a phone at once, which also lets you sign in, change settings and keep watching while you look for the remote. See how to use an Apple TV without the remote.
An Apple TV that is not on a network needs a remote, or an Ethernet cable to bring it online.
Volume on an Apple TV
The Apple TV has no volume of its own. Volume buttons control your TV or soundbar by infrared or HDMI‑CEC. From a phone, volume is passed through HDMI‑CEC, so that has to be on in the TV’s settings.