Not an iPhone app, so ignore if that's all you're interested in...


I print out a year's worth of sunrise/sunset data from the U.S. Naval Observatory. It's great for commuting (do I need lights?), and close enough for places within a few hours' drive:


http://aa.usno.navy.mil/data/docs/RS_OneYear.php


Note the site is pretty slow right now, probably has something to do with next month's eclipse.