"CloudSpotter covers 40 different types of clouds and pulls its information from Gavin Pretor-Pinney's Cloud Collector's Handbook. Besides the cloud itself, each listing also contains information on commonly confused clouds and clouds that are often seen together."
I'll be interviewing Gavin Pretor-Pinney on tonight's Your Mac Life (http://www.yourmaclifeshow.com). Tune in at 5:30pm PT, 8:30pm ET. http://www.tuaw.com/2013/06/25/daily-iphone-app-keep-your-eyes-on-the-sky-with-cloudspotter