SpaceStationAR

Best skill for satellite watching because:

Not only International Space Station, most of other visible satellites including Hubble Space Telescope, Chinese Space Station Tiangong and Iridium flares are all supported.

No need to say your city name. Just allow to access your postal code.

To get precise direction where to see, same name AR app is also available for iOS and Android.
http://ssar.space/free/