Here is the detailed link which explains everything.

Hi (Solution) I have faced this issue too. My application at the beginning checks some data through the internet so that for a little while it shows a loader at the screen. I have tested it many times before sending it to review and it was working on everywhere. But when apple guys starts testing on their iPad simulators they sent me a picture that my app was staying at the data checking screen and not launching. So guess what I did to them. I have prepared an internet checker against connection lose, and started to show some information on the screen like "Check your connection". Because I know on their iPad simulators internet connection is a problem. I have overcome this issue after getting rejection for 3 times. Try it guys, it will gonna work.