Hello, I just find that the IO (Jupiter's satellite) position is inaccurate, just now when SkySafari 5 Pro in Android shows IO is in transit with Jupiter, while in my telescope I can see IO finished transit, looks like the program is about 10-20 late for the IO's position. I'm sure the time, date and location are correct and we don't use day light saving here in Hong Kong (GMT+8)
I double checked in Stellarium and IO position is correct there.