Unfortunately (any) app has stopped. What should I report? When one gets the ever popular "such and such" app has stopped, you get offered the option to report it. What are you supposed to say in the "report"?
You'll want to help the developer to help you.

mbanzon's answer mentioned that the developer will receive the stack trace of the error, but that only tells us what went wrong and where.  

It does not tell us anything about the state the application is in: What was the value of that number, or what was the text that was entered in the text fields? And most importantly, what did the user exactly do to make the application crash? 

The latter question is especially important so that we can reproduce the error, and help us understand why the application crashed under these circumstances.

So if you want to really help the developers, write down what you did, what you expected, and what you saw. For example:


  I started the app and pressed the button to go to the reports screen. Then I pressed the button to generate the report, and the app crashed. Interestingly, the screen was blank: there was no data visible.


If you don't like typing much, you can be short:


  Pressed button to generate report. Screen was blank.