Page Monitor Pro is a free Chrome extension developed by My Extensions. This add-on stays in the background and monitors web pages for any changes. Whether you want to keep track of price changes on online shops or monitor any other element on websites, this extension has got you covered.

Page Monitor Pro is an open source fork of the original Page Monitor extension, now available under the MIT License. The developers have removed any tracking code and bloat from the extension, ensuring a streamlined and focused experience for users. They are also actively maintaining and developing the extension, with new features and design improvements currently in progress.

If you're looking for similar extensions or software, you can also check out Distill, Sitedelta Web Content Monitor and Refresh Monkey, as well as Wachete and Update Scanner for Firefox. For more comprehensive website monitoring solutions, you can explore Versionista, ChangeDetection, Alertbox, and OnWebChange.

With Page Monitor Pro, you can easily keep track of website changes and receive alerts whenever there's an update. Best of all, it's completely free to use.