Sun Surveyor - Sun Surveyor calculates Sun and Moon Positions, Sunrise & Sunset and Moonrise & Moonset...
Suntimes - Android app (and widget collection) that displays sunlight and moonlight times for a given location.
Natural Hour - A roman timekeeping add-on for Suntimes.
Sol: Sun Clock - Get reminded when it's sunrise or sunset, wherever you travel!
The Photographer's Ephemeris - TPE is a tool to help you plan outdoor photography in natural light, especially landscape and urban scenes. It is a map-centric sun, moon and milky way calculator: see how the light will fall on the land, day or night, for any location on earth.
Alpenglow - Never miss a incredible looking sunrise or sunset again