Celestial Navigator is a must have app for mariners and any other person interested in celestial navigation.
It features a rise set and merpass calculator, a line of position and compass error including gyro calculator , a celestial fix calculator (with auto run up and dead reckoning),an almanac of sun,moon,planets and 58 navigational stars.It supports the three most widely used navigational methods for calculation of lines of position i.e. intercept,long by chronometer and latitude by meridian altitude.
It also features a true wind calculator (giving wind speed and direction,dew point and relative humidity),an eta calculator (multiple results are shown at a time depending upon the user settings),a sailing calculator featuring great circle and Mercator sailing calculators along with intermediate point calculator.
It also displays the device's position(lat,long,speed,cog) from the GPS and the compass heading.
The accuracy of the results displayed has been thoroughly tested with the US navy website, the nautical almanac of 2013.The results are with in 10-15 seconds which is accurate enough for sea.
Please read the help carefully.

The app contains can export the almanac data and celestial observations data to the external SD card.