Before submitting a bug report, please check the iOS Troubleshooting page, where you will find solutions to common crashes and other problems.
If your application crashes in the Xcode debugger then you can add valuable information to your bug report as follows:-
Similarly, when reporting app freezes, you can click Pause and do the above steps.
If your application crashes on the iOS device, you should retrieve the crash report as described here on Apple’s website. Please attach the crash report, your built application and console log to your bug report before submitting.