Requirements: Android OS 2.1+
Price: $3.44
Overview: Mobile Observatory is a planetarium app for your mobile device which provides the following features:

- Zoomable sky map showing stars, planets, deep sky objects, ...
- Rise, set, and transit times for any object
- Position of any object in the sky (altitude and direction)
- Twilight times, length of day
- Bright Star and Messier Catalog (to be extended in future versions)
- Moon phases, the apparent view of the sun and planets
- Current image of the Sun and sun spot number
- Widget with rise & set times of the Sun and Moon
- Automatic location determination from the mobile network or GPS
- Select a location from a built-in database of 20 000 cities or online via Google Maps

- Choose any time and date
- Detailed ephemeris, visibility information of all objects
- Dates of conjunctions between any object with planets or the Moon (e.g. find the next conjunction of the Pleiades with the Moon)
- Animated 3D-view of the Moon and the planets
- Accurate calculations for dates between 1900 and 2100