A while ago I built a simple visual display for the current Austin-area air quality index: http://neilwebber.com/notes/2015/10/24/traffic-light-shows-air-quality-index/
The light was green for good AQI, yellow for medium, and red for bad air quality. For the AQI data I leveraged a “metric” that I had already developed using the Numerous service. Being a hard core nerd I also covered the case where the Numerous server could not be contacted; the display is red and yellow for that.
As you can see here, the error handling code works. Numerous shut down operations permanently on May 1, 2016 and my traffic light display is now simply a reminder of their demise. 🙁