Monitor Web Pages од Moris Papasmadov

Monitor web pages you are responsible for being available and not hijacked by malware.

Initial query interval is 5 minutes, change in options setting from 2 to 60 minutes.
Extension tab must be open for the scheduled query to repeat.
Track the badge icon color and counter for pages query status.

Not designed to track when your favorite shoes go for online store discount -
try VisualPing, Distill, Wachete and others to monitor page parts.