Which extension do I want?

Four, and they do not overlap. Each one answers a different question.

If the problem is…	Use	What it does	Price
Sites can tell you switched tabs — videos pause, timers stop, "are you still there?"	Anti-Blur	Makes the page believe it is always focused and visible.	Free
Ads, trackers, and pages that load slowly	Sodium	Blocks them before the request leaves, tidies what they leave behind, and preloads links you are about to click.	Free
Sites recognising you between visits even signed out	Argon	Changes the hardware, font and screen details a site reads to identify your browser.	Free
A site's typeface is unreadable, or you want your own	Typeswap	Puts a font of your choosing on any site.	Free

They work independently — running all four is fine, and none of them needs the others. Each is a zip on the download page.

How they run#

You load them into your own browser yourself. No program can put an extension into the browser you use every day — that is Chrome's rule, and it is the right one — but you can, and Chrome has always allowed it. Each extension is a zip on the download page, and unzipped it is a plain folder — which is exactly what Chrome's own Load unpacked wants.

Download the zip and unzip it.
In your browser open chrome://extensions and turn on Developer mode, top right.
Press Load unpacked and choose the unzipped folder — the one with manifest.json in it.

That one is yours: it runs on your everyday profile and it survives a restart. Updates are by hand — when a new version is out, download the zip again, replace the folder, and press Reload on the extension's card in chrome://extensions.

Downloading never depends on having Chrome open, or installed. What arrives is a folder; what you do with it is up to you.

Any Chromium browser

Edge, Brave, Vivaldi and Opera all have the same Developer mode and the same Load unpacked button. The extensions are ordinary Chromium extensions and nothing in them checks which browser they are in. Only Chrome is tested, which is a different claim from only Chrome working.

They are not the same as Perch#

Perch is an application, not an extension. It is the one that fences a screen share to a single tab and floats a window on top of your work. The extensions change how a page behaves; Perch changes what the browser hands out.

Perch does install one extension of its own into the Chrome it starts. That one is not in this list and is not optional — it is half of how Perch works, and it is described in How Perch works.

What none of them do#

None of the four sends anything anywhere. There is no account inside an extension, no analytics, and no server to talk to.