This is a very interesting and visually appealing app. I could spend hours looking at the orbits of different satellites. The info button provides a wealth of information about every satellite. The interface is very similar to sky safari, so thats helpful. Two suggestions: a 24-hour clock option in addition to AM/PM, and let the user define how far in advance to set alerts, or at least include options for earlier alert times. I would like to know about visible ISS flyovers 24 hours in advance so I can plan to see them.