Purple Platform Ad Non-Viewer от Kerdy

Twitch keeps your stream running in a small muted mini-player during ad breaks. This extension automates what you'd do by hand: it enlarges that mini stream to fill the player and unmutes it, while muting and covering the ad.

Not an ad blocker. The ad keeps playing to completion, stays on the page, and is counted normally meaning streamers still get their ad revenue. The only difference is what you see and hear.

Features:
• Automatic — detects the ad break, swaps, and restores when it ends
• Mute button on the stream during ads (carried over after the ad if you toggle it)
• Respects your mute state — if you were watching muted, it stays muted
• No data collection, no external servers, works entirely on twitch.tv

Note: this relies on Twitch serving picture-by-picture ads (the corner mini-player). If Twitch shows you a regular full-screen ad without the mini stream, the extension stays dormant.