We have some trouble with SkySafari 6 under iOS: the ISS position seems to be displayed wrong. On Android devices the position is correct.
One example: tue, 22. sept. 19:14h: on iOS the ISS comes above horizen (which is not true!), on android the position is displayed correctly.
It seems, that the time calculation is wrong: ISS was visible on 22.sept. from ca. 20:04 until 20:15h
On both devices (iOS and android) the same observing location (near Frankfurt/Main) is set. A friend with an iPhone has exactly the same problem.