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.
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
Distill Web Monitor - Distill is a web monitoring tool. It can monitor RSS feeds, a webpage or a part of webpage. Alerts in the form of pop-up, audio or emails can be received.
Monkey Test It - Primate powered algorithms that scan your site for common bugs and SEO mistakes.
PageProbe - Automatic Page Monitor - Create automatic monitors for detecting and scanning changes on web pages, evaluate content based...
NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.