Monitoring the performance of your rails application is easy with New Relic. When I shared my munin charting for New Relic I mentioned I was building a status bar. At the time it was ugly and didn't work with multiple accounts. After using New Relic to fix an issue on cliKball this evening I decided to improve the extension.
After entering your license key (found in the Accounts tab of your dashboard), your application's health is checked every minute, showing the traffic lights for your selected app. To change between your applications you can click on the new relic dropdown menu. Hovering on the traffic light gives you more information, clicking on the lights takes you to the overview for your application.
Installation and source
From Firefox click http://s3.amazonaws.com/overstimulate/relic.xpi to install (you might need to click "allow" in the upper right corner of your browser after the first click).
The source is on github at anotherjesse/foxy-relic.
