<i>Change Detection</i> tracks changes on websites you otherwise would visit frequently to see if there is something new. Use cases: * Teacher says grades will be published "soon", but no one knows what "soon" means and you are tired of reloading. * You are working with a server and wants to know the result from a request, periodically. * You are waiting for updates on an Exam, like if something was postponed or updated. * You want to monitor the Dagger documentation to see when Thermosiphon's explanation improves.