On videos you can see how to control volume on Hi-Fi receiver and control lights with voice.
Under the video are links and description how I made this.
Everything is very simple and without coding;)
Step 1: Turn ON/OFF Lights With Smart Watch
I have previous version. I use it to control lights with IR remote - Logitech Harmony One, and the lights wake me up at morning:)
Step 2: How to Change Volume on Hi-Fi With Smart Watch
MyAV TV app
Works with almost any receiver with ethernet or wifi connection.
Just install and that's it:)
App have some "bug" (I think). Like you can see on video, app opens on phone when you use it on watch.