WebSentinel 2.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This Mac app is an intellectual property of By Limit Point Software. The application lies within Communication Tools, more precisely General.
From the developer:
WebSentinel is a utility for monitoring the content of web pages for search terms at a scheduled time, optionally on a periodic basis.
Drag and drop URLs or use the "Current Browser" button to add URLs to the list window. Then Click in the "Search Terms" column of each row to open an editor, and then type or copy the terms you want to search for in the content of the corresponding URL.