Nagios is great. It monitors all your stuff, uses email/sms/text-to-speech/carrier pigeon to notify you when stuff goes down and has a handy-dandy web interface for keeping track of everything, however sometimes you want more, because you’re greedy.
This helpful floaty-widget thing will keep you notified of any changes to the status of your Nagios-monitored devices, lets you acknowledge & recheck services and supports multiple Nagios instances.
cnagios is a full-screen terminal interface for viewing Nagios host and service objects and the durations of their current states, using ncurses. It’s very handy if you’re limited to SSH connectivity to your Nagios server. The site it’s hosted on appears to be down at the moment, so hopefully the author won’t mind me hosting a copy of it for the time being: cnagios-0.29.tar.gz
Nagroid is an unofficial nagios client for android devices, which is handy because the standard web interface doesn’t play nicely with smartphone-sized screens.
Nagios Checker is a Firefox addon that presents a status bar display of the status of your Nagios-monitored devices, similar to nagstamon. It’s very handy if you spend most of your day stuck in a web browser.
So there you go; now you’ve got no excuse for missing that service or server down alert.