docs: Add guide on how to simulate real apps in ndnSIM

Change-Id: I3694a8791b9540fc1b926a83ff55421b47e0f2a2
diff --git a/examples/ndn-cxx-simple.cpp b/examples/ndn-cxx-simple.cpp
new file mode 100644
index 0000000..22497e0
--- /dev/null
+++ b/examples/ndn-cxx-simple.cpp
@@ -0,0 +1,60 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2011-2015  Regents of the University of California.
+ *
+ * This file is part of ndnSIM. See AUTHORS for complete list of ndnSIM authors and
+ * contributors.
+ *
+ * ndnSIM is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndnSIM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndnSIM, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+#include "ndn-cxx-simple/real-app.hpp"
+#include "ndn-cxx-simple/real-app-starter.hpp"
+
+#include "ns3/core-module.h"
+#include "ns3/network-module.h"
+#include "ns3/ndnSIM-module.h"
+
+namespace ns3 {
+
+NS_OBJECT_ENSURE_REGISTERED(RealAppStarter);
+
+int
+main(int argc, char* argv[])
+{
+  CommandLine cmd;
+  cmd.Parse(argc, argv);
+
+  Ptr<Node> node = CreateObject<Node>();
+
+  ndn::StackHelper ndnHelper;
+  ndnHelper.Install(node);
+
+  ndn::AppHelper appHelper("RealAppStarter");
+  appHelper.Install(node)
+    .Start(Seconds(6.5));
+
+  Simulator::Stop(Seconds(20.0));
+
+  Simulator::Run();
+  Simulator::Destroy();
+
+  return 0;
+}
+
+} // namespace ns3
+
+int
+main(int argc, char* argv[])
+{
+  return ns3::main(argc, argv);
+}