diff --git a/viewer/js/config/viewer.js b/viewer/js/config/viewer.js
index 9569a7007..39b0194b2 100644
--- a/viewer/js/config/viewer.js
+++ b/viewer/js/config/viewer.js
@@ -53,6 +53,7 @@ define([
             zoom: 5,
             sliderStyle: 'small'
         },
+
         // panes: {
         // 	left: {
         // 		splitter: true
@@ -81,6 +82,29 @@ define([
         // },
         // collapseButtonsPane: 'center', //center or outer
 
+        // custom titles
+        /*
+        titles: {
+            header: 'My App',
+            subHeader: 'My GIS App is the best!',
+            pageTitle: 'My App'
+        },
+        */
+
+        // user-defined layer types
+        /*
+        layerTypes: {
+            myCustomLayer: 'widgets/MyCustomLayer'
+        },
+        */
+
+        // user-defined widget types
+        /*
+        widgetTypes: [
+            'myWidgetType'
+        ],
+        */
+
         // operationalLayers: Array of Layers to load on top of the basemap: valid 'type' options: 'dynamic', 'tiled', 'feature'.
         // The 'options' object is passed as the layers options for constructor. Title will be used in the legend only. id's must be unique and have no spaces.
         // 3 'mode' options: MODE_SNAPSHOT = 0, MODE_ONDEMAND = 1, MODE_SELECTION = 2
diff --git a/viewer/js/gis/dijit/LayerControl.js b/viewer/js/gis/dijit/LayerControl.js
index a47cb8c5b..c1158b1f0 100644
--- a/viewer/js/gis/dijit/LayerControl.js
+++ b/viewer/js/gis/dijit/LayerControl.js
@@ -85,6 +85,8 @@ define([
                 });
                 return;
             }
+            // add any user-defined controls - possibly for user-defined layers
+            this._controls = lang.mixin(this._controls, options.controls || {});
         },
         postCreate: function () {
             this.inherited(arguments);
diff --git a/viewer/js/viewer/_MapMixin.js b/viewer/js/viewer/_MapMixin.js
index 57cd22244..4806d7e75 100644
--- a/viewer/js/viewer/_MapMixin.js
+++ b/viewer/js/viewer/_MapMixin.js
@@ -60,34 +60,36 @@ define([
         _initLayers: function (returnWarnings) {
             this.layers = [];
             var layerTypes = {
-                csv: 'CSV',
-                dataadapter: 'DataAdapterFeature', //untested
-                dynamic: 'ArcGISDynamicMapService',
-                feature: 'Feature',
-                georss: 'GeoRSS',
-                image: 'ArcGISImageService',
-                imagevector: 'ArcGISImageServiceVector',
-                kml: 'KML',
-                label: 'Label', //untested
-                mapimage: 'MapImage', //untested
-                osm: 'OpenStreetMap',
-                raster: 'Raster',
-                stream: 'Stream',
-                tiled: 'ArcGISTiledMapService',
-                vectortile: 'VectorTile',
-                webtiled: 'WebTiled',
-                wfs: 'WFS',
-                wms: 'WMS',
-                wmts: 'WMTS' //untested
+                csv: 'esri/layers/CSVLayer',
+                dataadapter: 'esri/layers/DataAdapterFeatureLayer', //untested
+                dynamic: 'esri/layers/ArcGISDynamicMapServiceLayer',
+                feature: 'esri/layers/FeatureLayer',
+                georss: 'esri/layers/GeoRSSLayer',
+                image: 'esri/layers/ArcGISImageServiceLayer',
+                imagevector: 'esri/layers/ArcGISImageServiceVectorLayer',
+                kml: 'esri/layers/KMLLayer',
+                label: 'esri/layers/LabelLayer', //untested
+                mapimage: 'esri/layers/MapImageLayer', //untested
+                osm: 'esri/layers/OpenStreetMapLayer',
+                raster: 'esri/layers/RasterLayer',
+                stream: 'esri/layers/StreamLayer',
+                tiled: 'esri/layers/ArcGISTiledMapServiceLayer',
+                vectortile: 'esri/layers/VectorTileLayer',
+                webtiled: 'esri/layers/WebTiledLayer',
+                wfs: 'esri/layers/WFSLayer',
+                wms: 'esri/layers/WMSLayer',
+                wmts: 'esri/layers/WMTSLayer' //untested
             };
+            // add any user-defined layer types such as https://github.com/Esri/geojson-layer-js
+            layerTypes = lang.mixin(layerTypes, this.config.layerTypes || {});
             // loading all the required modules first ensures the layer order is maintained
             var modules = [];
             array.forEach(this.config.operationalLayers, function (layer) {
                 var type = layerTypes[layer.type];
                 if (type) {
-                    modules.push('esri/layers/' + type + 'Layer');
+                    modules.push(type);
                 } else {
-                    returnWarnings.push('Layer type "' + layer.type + '"" isnot supported: ');
+                    returnWarnings.push('Layer type "' + layer.type + '" is not supported: ');
                 }
             }, this);
 
@@ -95,7 +97,7 @@ define([
                 array.forEach(this.config.operationalLayers, function (layer) {
                     var type = layerTypes[layer.type];
                     if (type) {
-                        require(['esri/layers/' + type + 'Layer'], lang.hitch(this, '_initLayer', layer));
+                        require([type], lang.hitch(this, '_initLayer', layer));
                     }
                 }, this);
                 this.map.addLayers(this.layers);
diff --git a/viewer/js/viewer/_WidgetsMixin.js b/viewer/js/viewer/_WidgetsMixin.js
index 78dc52f41..22624d9a3 100644
--- a/viewer/js/viewer/_WidgetsMixin.js
+++ b/viewer/js/viewer/_WidgetsMixin.js
@@ -79,8 +79,10 @@ define([
         widgetLoader: function (widgetConfig, position) {
             var parentId, pnl;
 
-            // only proceed for valid widget types
             var widgetTypes = ['titlePane', 'contentPane', 'floating', 'domNode', 'invisible', 'map'];
+            // add any user-defined widget types
+            widgetTypes = widgetTypes.concat(this.config.widgetTypes || []);
+            // only proceed for valid widget types
             if (array.indexOf(widgetTypes, widgetConfig.type) < 0) {
                 this.handleError({
                     source: 'Controller',