Sun Surveyor - Sun Surveyor calculates Sun and Moon Positions, Sunrise & Sunset and Moonrise & Moonset...
SkinVision - App to detect skin cancer - with 70%+ accuracy
Sol: Sun Clock - Get reminded when it's sunrise or sunset, wherever you travel!
SkinTheory - Control your acne. Scientifically.
Suntimes - Android app (and widget collection) that displays sunlight and moonlight times for a given location.
Sunscreen Finder - Find the sunscreen that you will actually use