openpom is a Web interface based on NDO for Nagios or Icinga. It allows you to view almost everything about Nagios or Icinga in a single page: alert, ack, downtime, comment. You can also interact with Nagios or Icinga through ack, downtime, comment, disable, and reset buttons. You can filter on hosts and services states (such as critical, warning, unknown, ok, or outage). The status popin allows you to display graphs, either the ones from Nagios (trends.cgi) or custom ones based on RRD (such as pnp4nagios).
Panoptes is a scalable, extensible network and host monitoring tool. It includes a dynamic Web management interface based on the Dojo toolkit. It monitors SNMP, TCP port availability, ICMP, HTTP response and content, and SSL certificates internally. It supports monitoring anything else via shell scripts. It also includes a packet capture tool for discovery of hosts, port, and OS.
OpMon is a network and system monitoring application based on Nagios with extended support for capacity planning, SLA, SLM, network discovery, service catalogs, report schedule, Davinci, a dashboard builder, and much more. OpMon provides a GUI for Nagios as well as full multi-language support. The license to use the opmon proprietary modules is free for 2 hosts and 20 services. OpMon comes with many open source applications like phplogcon, Nedi, ntop, nagtrap, OCSInventory, OTRS, and opcfg.
Nagios 4 iPhone is a Nagios interface for the iPhone. It does not require any modifications on your Nagios servers. The server part of this software collects statistics on several Nagios servers, serves a few static files, and generates a JSON response. The client part handles the display of the data on the iPhone.