WebChangeMonitor

Is a software, contrary to most solutions requiring you to use a browser extension or register online so they can spy on what you want to track. Does the job pretty well. I have seen the app evolve and improve thanks to an active developer who release a new version every month. Linux compatible was a great surprise. Imo the best solution if you want a standalone app to monitor changes on websites.

Benefits: Seems to be the only completely free Windows app for tracking changes on sites at the end of 2021. Apart from browser add-ons. Disadvantages: first, the insertion of "Item's settings" / "Specify Content ..." of the constructs [p id = "..." class = "..."] and [div class = "..."] (taken from from the monitored web page) prevented the application from seeing the changes being made to the page. "Inspect items content" displays the desired page fragment. At the same time, the constraints [div class = "..."] and [footer] did not cause an error. And secondly, notifications are displayed in a stack, and only the last one is visible. But, most importantly, the application does not seem to work. At least visual highlighting of the tracking area, as is done in AdBlock Plus, would not hurt.

* Replaced triangular brackets with square brackets here.