It's an open source planetarium software Stellarium. Can be downloaded free from stellarium.org
Note that although it simulates the day/night sky quite realistically, it cannot be used to predict the first/last visibility of the crescent Moon - because it was not designed for that (planetarium software plot position and orientation only) and does not and cannot simulate or predict atmospheric conditions. In fact, no software can forecast the actual visual appearance of a celestial target. You can, however, use it to see the exact location of the Moon on a given date and time.
There are other tools and resources which forecast the astronomical visibility prospects of the new crescent Moon; actual sighting depends upon your local weather, of course. J
