Chrome users on Mac, Linux and PC can install Accompany for Gmail from the Chrome Store directly using this link.
Once you install the extension, it will prompt you to sign up or log in if you're not already logged in to the Accompany web app.
By default, Chrome extensions update every 5 hours or so. If you need to update the extension manually, choose "Update Extensions Now" from chrome://extensions.
To uninstall Accompany for Gmail, open chrome://extensions and click the trash icon next to Accompany for Gmail.