If an app crashes while I’m using it in OS X I get a little (apparently) OS-driven dialog that lets me “report the crash to Apple”. It sends along a stack trace and some other system information.
Does this crash information get shared with the app developer of the app in question at the time the crash occurred?
iTunes Connect will let you get crash reports for your apps sold through the App Store. For all other apps, you’ll need to implement your own crash reporting. (I mean, the Crash Reporter dialog shows up either way, but if you’re not selling through iTunes Connect, there’s no automatic way to get the information it collects.)