Page2RSS is described as 'Service that helps you monitor web sites that do not publish feeds. It will check any web page for updates and deliver them to your favorite RSS reader' and is a website monitoring tool in the network & admin category. There are more than 10 alternatives to Page2RSS, not only websites but also apps for a variety of platforms, including Windows, Linux, Mac and Mozilla Firefox apps. The best Page2RSS alternative is Distill Web Monitor, which is free. Other great sites and apps similar to Page2RSS are Portia, FetchRSS, WebSite-Watcher and import.io.
Page2RSS provided an RSS feed showing differences in a page when it was updated. But Portia is a tool to scrape data from a page. So you cannot see if the page has changed.