ManageEngine Applications Manager is an availability and performance monitoring software that helps businesses ensure high availability and performance for their business applications by ensuring servers and applications have high uptime. The application performance management capability includes server monitoring, application server monitoring, database monitoring, web services monitoring and an array of other application management capability that will help IT administrators manage their resources.

They have free edition with limited number of monitors. Evaluate and download at:

Download ManageEngine Applications Manager – Free Edition and Professional Edition Trial