If you'd like to track visits to your site, you can use our built-in widget of Google Analytics once you connect your site to a domain.
Copy&paste the tracking ID from google and insert it under Settings --> Google Analytics in the editor. This is the only place to put it in the site, no need to insert it on each page.
To connect your site to a domain, click PUBLISH > choose a subscription > follow the steps in our wizard to connect it or buy a new domain from us (if you buy a domain from us, we will then email you within 48 hours that the site is up)
For more info, please see Google's post.
if you wish to use other tracking software, please request their HTML code from them and embed it to your site through Add Element > HTML.