Uptime Robot is a free online service that provides uptime monitoring for your websites. It allows you to add up to 50 websites and alerts you if your sites are down via e-mail or SMS. It checks your websites every 5 minutes and can notify multiple users in case of a downtime.
Uptime Robot supports both http and https addresses, enabling you to ensure secure pages and SSL certificate are functioning properly. Setting up and using the service is very easy and it has a simple and fully Ajaxed interface for a faster usage.
Developed by Umut Muhaddisoglu (WebResourcesDepot) and Daniel Rimille(SSLmatic); Uptime Robot is available as a free service until 01 August 2010 (the service is intended to remain free forever – depending on support from sponsors and advertisements). You can signup and get further details on Uptime Robot Website.