Added an example of how to configure debugging with run_simple, it has to be enabled both for the Flask app and the Werkzeug server.

docs/patterns/appdispatch.rst

@@ -30,6 +30,23 @@ at :func:`werkzeug.serving.run_simple`::
 Note that :func:`run_simple <werkzeug.serving.run_simple>` is not intended for
 use in production.  Use a :ref:`full-blown WSGI server <deployment>`.
 
+In order to use the interactive debuggger, debugging must be enables both on 
+the application and the simple server, here is the "hello world" example with debugging and 
+:func:`run_simple <werkzeug.serving.run_simple>` :
+
+    from flask import Flask
+    from werkzeug.serving import run_simple
+
+    app = Flask(__name__)
+    app.debug = True
+
+    @app.route('/')
+    def hello_world():
+        return 'Hello World!'
+
+    if __name__ == '__main__':
+        run_simple('localhost', 5000, app, use_reloader=True, use_debugger=True, use_evalex=True)
+
 
 Combining Applications
 ----------------------