Frigid is an Arduino program designed to monitor the temperature and humidity of the inside of a refrigerator. However, it can be used in just about any environment.
Frigid displays the temperature and humidity as simple moving averages over the last minute, hour, and day. This idea is inspired by load average displays on Unix systems. This display style allows the user to get a rough sense of the temperature stability over time.
Here's a photo of what the display looks like:
(Averages that have not been computed yet appear as 0.)