>Shows a notif the instant a Twitch streamer you added to the list goes live
https://github.com/joaopsys/NowStreaming

>Same thing but for Youtube
https://streamlive.fadme.dev/

>Lets you take screenshots directly from the stream on your browser and has other cool stuff
https://previews-app.com/

>Useful for keeping track of schedules
https://le0michine.github.io/worldtime-extension/

and of course, can't forget AdSolutions https://github.com/pixeltris/TwitchAdSolutions