No, so long as you can paste the Guidethrough code snippet into your web application or website's HTML your end users don't need to do anything.

Once you add your specific account's Guidethrough code snippet to your application or website, your users can then see the published Guidethroughs (web tours) without installing the Guidethrough Player Chrome browser extension.

In this way Guidethrough will work for your end users across modern browsers like Chrome, Safari, Firefox, IE etc.

If you don't have access to your web application or website's HTML, then your end users can use the Guidethrough Player Chrome extension to view and play your published Guidethroughs.