1)   ManageEngine OpManager Free Edition 5.5
ManageEngine OpManager is a comprehensive, easy to use Network, Systems and Applications monitoring software that offers integrated fault and performance management functionality
Network Monitoring, Network Management, Fault Management, Performance Monitoring, Manage Apps, DB, WAN, LAN, Switches, Routers,

 2)   Easy Network Service Monitor 2.14
Easy to use and low cost tool for network, applications and services monitoring, fault identification, notification and reporting as well as service level agreement monitoring and reporting.
server, service level agreement, sla, network monitor, network applications, network availability, network troubleshooting, fault management, network management, network performance,