Android: Sundroid is a simple but effective tool for checking the cycles of the sun and moon based on your physical location, right from your Android phone.
If your work or recreational activities are dependent on markers like sunrise or sunset (the shooting range I belong to, for example, shuts down the outdoor ranges at sunset) Sundroid will keep you abreast of the times.
Sundroid comes in free and premium flavours. The free version displays the sunrise, sunset, moonrise and moonset times for your location. The ~$2.07 premium version adds in twilight times, azimuths, a lunar calendar and a home screen widget. Sundroid uses your GPS or WiFi network IP location for geolocation.
Sundroid Free Sunrise/Sunset [AppBrain]