The stable version is available on both the Chrome Web Store and Firefox Add-ons. Install from there for automatic updates.
Get early access to new features before they hit the stores.
Chrome beta builds require developer mode to install.
Click "Download Beta" above to get the latest build.
Extract the .zip and keep the folder - Chrome needs it to stay in place.
Navigate to chrome://extensions in your browser.
Toggle "Developer mode" in the top-right corner.
Select the folder where you extracted the zip.
The beta is now running alongside (or instead of) the store version.
Install from the official stores for automatic updates and no developer mode needed.