This app does precisely what I've been looking for. It offers a way to display where the GPS family of satellites are over my location. In large cities where tall buildings often block GPS coverage, that'll give me an idea where I need to be to see them.
Selecting the various families of satellites, including GPS (U.S), GLONASS (Russian) and Galileo (European) as well as Iridium and the ISS is quite easy, far easier that checking off the individual satelllites in a long list. One enhancement would make that feature still better. Presently, selecting Galileo deselects GPS. Since a GPS device will use both, it'd be handy to be able to select both at the same time.
The developer might also leverage his labors and create a speciality app for each family of satellites. Someone who uses Iridium for remote data or a satellite phone, for instance, might want a easy way to see just them. In the case of Iridium, the app might also display their present availability.
I like its thoughtfully dark UI too. I can use it outside at night without losing my night vision.