TwitchMe автор MasteOfHollows

Features
Add channels to a watch list
Auto-opens stream tabs when a channel goes live
Re-opens tabs if you close them while the stream is still live
Per-channel settings: mute (tab-level), auto-focus, number of tabs to open
It makes sure that the twitch player has audio on
Polling interval: 15s, 30s, 1min, or 5min
Optionally close tabs when the stream ends

I wouldn't say no to a tip :D
https://ko-fi.com/masterofhollows
Code:
https://github.com/grepfs17/twitchme-firefox