Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
Sken.io - The most advanced tools for tracking changes on websites.
WebSite-Watcher - WebSite-Watcher detects website updates and highlights all changes in the text. WebSite-Watcher monitors web pages, password protected pages, disucssion forums and much more.
ChangeTower - ChangeTower offers website monitoring tools for new content and content changes.
Update Scanner - Update Scanner is a Firefox extension to monitor web pages for updates.
Wachete - Track web page changes and get notified. Free Sign-up. Have all data in one place