PreviSat is a satellite tracking software for observing purposes. Very easy to use, it shows the positions of the satellites in real-time or manual mode. PreviSat is able to make predictions of their passes and also predictions of Iridium flares. It features NORAD SGP4 model (Vallado, 2006, Topocentric, Equatorial, and Terrestrial coordinates (satellites, Sun, Moon), osculating elements, satellite information,and prediction of passes, Iridium flares, orbital events, and ISS transits.