Add remark about setting exception breakpoints to Objective-C only.

README.md

@@ -413,7 +413,7 @@ _(Note: all Futurice employees get a free license to this — just ask Ali.)_
 
 ### Debugging
 
-It's a good idea to add an exception breakpoint (click the "+" at the bottom of Xcode's Debug Navigator) to halt execution whenever the app is about to crash. In many cases, you will then see the line of code responsible for the exception.
+When your app crashes, Xcode does not break into the debugger by default. To achieve this, add an exception breakpoint (click the "+" at the bottom of Xcode's Debug Navigator) to halt execution whenever an exception is raised. In many cases, you will then see the line of code responsible for the exception. This catches any exception, even handled ones. If Xcode keeps breaking on benign exceptions in third party libraries e.g., you might be able to mitigate this by choosing Edit Breakpoint and setting the Exception drop-down to "Objective-C". 
 
 For view debugging, [Reveal][reveal] and [Spark Inspector][spark-inspector] are two powerful visual inspectors that can save you hours of time, especially if you're using Auto Layout and want to locate views that are collapsed or off-screen. Granted, Xcode offers [something very similar][xcode-view-debugging] for free, but it's iOS 8+ only and feels somewhat less polished.