NaviStar is an app for professional and academic use in the maritime field. It’s main functionality is to perform astronomical repositioning through the determinants calculation and solving the altitude lines crossing. We think that NaviStar will be a very useful tool for seafarers. Note that in case of “Black Out” or GPS offline, celestial Navigation would be their only possibility to safely proceed to port. NaviStar App would help seafarers providing the calculation of its truth position and reducing the time to do so. Also, the print option of NaviStar results would provide evidence of their observations to authority surveyors. Available Calculations Algorithms: -Simultaneous Observation (*Graphical Representation Included) -Quasi Simultaneous Observation (*Graphical Representation Included) -Non Simultaneous Observation (*Graphical Representation Included) -Meridian Observation -Latitude Calculation through Polaris -Celestial Bodies Recognition -Morning/Evening Twilight Planning -Sunrise/Sunset Planning -Moonrise/Moonset Planning *Results Graphical Representation on Plotting Chart.