Added am:app service stub.

Apparently nothing at all is known about this service...

src/core/hle/service/am_app.cpp

@@ -0,0 +1,23 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "common/log.h"
+#include "core/hle/hle.h"
+#include "core/hle/service/am_app.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Namespace AM_APP
+
+namespace AM_APP {
+
+const Interface::FunctionInfo FunctionTable[] = {
+};
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Interface class
+
+Interface::Interface() {
+    Register(FunctionTable, ARRAY_SIZE(FunctionTable));
+}
+
+} // namespace

src/core/hle/service/am_app.h

@@ -0,0 +1,27 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/service.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Namespace AM_APP
+
+namespace AM_APP {
+
+class Interface : public Service::Interface {
+public:
+    Interface();
+
+    /**
+     * Gets the string port name used by CTROS for the service
+     * @return Port name of service
+     */
+    std::string GetPortName() const override {
+        return "am:app";
+    }
+};
+
+} // namespace

src/core/hle/service/service.cpp

@@ -7,6 +7,7 @@
 
 #include "core/hle/service/service.h"
 #include "core/hle/service/ac_u.h"
+#include "core/hle/service/am_app.h"
 #include "core/hle/service/am_net.h"
 #include "core/hle/service/apt_u.h"
 #include "core/hle/service/boss_u.h"
@@ -84,6 +85,7 @@ void Init() {
 
     g_manager->AddService(new SRV::Interface);
     g_manager->AddService(new AC_U::Interface);
+    g_manager->AddService(new AM_APP::Interface);
     g_manager->AddService(new AM_NET::Interface);
     g_manager->AddService(new APT_U::Interface);
     g_manager->AddService(new BOSS_U::Interface);