diff --git a/js/fractions-mixed-numbers-main.js b/js/fractions-mixed-numbers-main.js
index aba8572..e7ea091 100644
--- a/js/fractions-mixed-numbers-main.js
+++ b/js/fractions-mixed-numbers-main.js
@@ -5,20 +5,20 @@
  *
  * @author Jonathan Olson <jonathan.olson@colorado.edu>
  */
-define( function( require ) {
+define( require => {
   'use strict';
 
   // modules
-  var GameScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/GameScreen' );
-  var IntroScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/IntroScreen' );
-  var LabScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/LabScreen' );
-  var Sim = require( 'JOIST/Sim' );
-  var SimLauncher = require( 'JOIST/SimLauncher' );
+  const GameScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/GameScreen' );
+  const IntroScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/IntroScreen' );
+  const LabScreen = require( 'FRACTIONS_MIXED_NUMBERS/view/LabScreen' );
+  const Sim = require( 'JOIST/Sim' );
+  const SimLauncher = require( 'JOIST/SimLauncher' );
 
   // strings
-  var fractionsMixedNumbersTitleString = require( 'string!FRACTIONS_MIXED_NUMBERS/fractions-mixed-numbers.title' );
+  const fractionsMixedNumbersTitleString = require( 'string!FRACTIONS_MIXED_NUMBERS/fractions-mixed-numbers.title' );
 
-  var simOptions = {
+  const simOptions = {
     credits: {
       //TODO fill in proper credits, all of these fields are optional, see joist.AboutDialog
       leadDesign: '',
@@ -30,8 +30,8 @@ define( function( require ) {
     }
   };
 
-  SimLauncher.launch( function() {
-    var sim = new Sim( fractionsMixedNumbersTitleString, [
+  SimLauncher.launch( () => {
+    const sim = new Sim( fractionsMixedNumbersTitleString, [
       new IntroScreen(),
       new GameScreen(),
       new LabScreen()
diff --git a/js/fractionsMixedNumbers.js b/js/fractionsMixedNumbers.js
index bddb436..3b967bd 100644
--- a/js/fractionsMixedNumbers.js
+++ b/js/fractionsMixedNumbers.js
@@ -5,11 +5,11 @@
  *
  * @author Jonathan Olson <jonathan.olson@colorado.edu>
  */
-define( function( require ) {
+define( require => {
   'use strict';
 
   // modules
-  var Namespace = require( 'PHET_CORE/Namespace' );
+  const Namespace = require( 'PHET_CORE/Namespace' );
 
   return new Namespace( 'fractionsMixedNumbers' );
 } );
\ No newline at end of file
diff --git a/js/view/GameScreen.js b/js/view/GameScreen.js
index e5f83e9..3a8f467 100644
--- a/js/view/GameScreen.js
+++ b/js/view/GameScreen.js
@@ -1,42 +1,36 @@
 // Copyright 2018, University of Colorado Boulder
 
 /**
- * TODO: doc
+ * Game screen for Fractions: Mixed Numbers
  *
  * @author Jonathan Olson <jonathan.olson@colorado.edu>
  */
-define( function( require ) {
+define( require => {
   'use strict';
 
   // modules
-  var BuildingGameModel = require( 'FRACTIONS_COMMON/game/model/BuildingGameModel' );
-  var BuildingGameScreenView = require( 'FRACTIONS_COMMON/game/view/BuildingGameScreenView' );
-  var FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
-  var fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
-  var inherit = require( 'PHET_CORE/inherit' );
-  var Screen = require( 'JOIST/Screen' );
+  const BuildingGameModel = require( 'FRACTIONS_COMMON/game/model/BuildingGameModel' );
+  const BuildingGameScreenView = require( 'FRACTIONS_COMMON/game/view/BuildingGameScreenView' );
+  const FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
+  const fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
+  const Screen = require( 'JOIST/Screen' );
 
   // strings
-  var screenGameString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.game' );
-
-  /**
-   * @constructor
-   */
-  function GameScreen() {
-
-    var options = {
-      name: screenGameString,
-      backgroundColorProperty: FractionsCommonColorProfile.otherScreenBackgroundProperty
-    };
-
-    Screen.call( this,
-      function() { return new BuildingGameModel( true ); },
-      function( model ) { return new BuildingGameScreenView( model ); },
-      options
-    );
+  const screenGameString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.game' );
+
+  class GameScreen extends Screen {
+    constructor() {
+      super(
+        () => new BuildingGameModel( true ),
+        model => new BuildingGameScreenView( model ),
+        {
+          name: screenGameString,
+          backgroundColorProperty: FractionsCommonColorProfile.otherScreenBackgroundProperty,
+          homeScreenIcon: BuildingGameScreenView.createMixedScreenIcon()
+        }
+      );
+    }
   }
 
-  fractionsMixedNumbers.register( 'GameScreen', GameScreen );
-
-  return inherit( Screen, GameScreen );
+  return fractionsMixedNumbers.register( 'GameScreen', GameScreen );
 } );
diff --git a/js/view/IntroScreen.js b/js/view/IntroScreen.js
index 5103a99..b261e5e 100644
--- a/js/view/IntroScreen.js
+++ b/js/view/IntroScreen.js
@@ -1,42 +1,37 @@
 // Copyright 2018, University of Colorado Boulder
 
 /**
- * TODO: doc
+ * Intro screen for Fractions: Mixed Numbers
  *
  * @author Jonathan Olson <jonathan.olson@colorado.edu>
  */
-define( function( require ) {
+define( require => {
   'use strict';
 
   // modules
-  var FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
-  var fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
-  var inherit = require( 'PHET_CORE/inherit' );
-  var IntroModel = require( 'FRACTIONS_COMMON/intro/model/IntroModel' );
-  var IntroScreenView = require( 'FRACTIONS_COMMON/intro/view/IntroScreenView' );
-  var Screen = require( 'JOIST/Screen' );
+  const FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
+  const fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
+  const IntroModel = require( 'FRACTIONS_COMMON/intro/model/IntroModel' );
+  const IntroScreenView = require( 'FRACTIONS_COMMON/intro/view/IntroScreenView' );
+  const Screen = require( 'JOIST/Screen' );
 
   // strings
-  var screenIntroString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.intro' );
-
-  /**
-   * @constructor
-   */
-  function IntroScreen() {
-
-    var options = {
-      name: screenIntroString,
-      backgroundColorProperty: FractionsCommonColorProfile.introScreenBackgroundProperty
-    };
-
-    Screen.call( this,
-      function() { return new IntroModel( true ); },
-      function( model ) { return new IntroScreenView( model ); },
-      options
-    );
+  const screenIntroString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.intro' );
+
+  class IntroScreen extends Screen {
+    constructor() {
+      super(
+        () => new IntroModel( true ),
+        model => new IntroScreenView( model ),
+        {
+          name: screenIntroString,
+          backgroundColorProperty: FractionsCommonColorProfile.introScreenBackgroundProperty,
+          homeScreenIcon: IntroScreenView.createMixedScreenIcon(),
+          navigationBarIcon: IntroScreenView.createMixedScreenThumbnail()
+        }
+      );
+    }
   }
 
-  fractionsMixedNumbers.register( 'IntroScreen', IntroScreen );
-
-  return inherit( Screen, IntroScreen );
+  return fractionsMixedNumbers.register( 'IntroScreen', IntroScreen );
 } );
diff --git a/js/view/LabScreen.js b/js/view/LabScreen.js
index 82506ce..b668e18 100644
--- a/js/view/LabScreen.js
+++ b/js/view/LabScreen.js
@@ -1,42 +1,36 @@
 // Copyright 2018, University of Colorado Boulder
 
 /**
- * TODO: doc
+ * Lab screen for Fractions: Mixed Numbers
  *
  * @author Jonathan Olson <jonathan.olson@colorado.edu>
  */
-define( function( require ) {
+define( require => {
   'use strict';
 
   // modules
-  var BuildingLabModel = require( 'FRACTIONS_COMMON/lab/model/BuildingLabModel' );
-  var BuildingLabScreenView = require( 'FRACTIONS_COMMON/lab/view/BuildingLabScreenView' );
-  var FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
-  var fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
-  var inherit = require( 'PHET_CORE/inherit' );
-  var Screen = require( 'JOIST/Screen' );
+  const BuildingLabModel = require( 'FRACTIONS_COMMON/lab/model/BuildingLabModel' );
+  const BuildingLabScreenView = require( 'FRACTIONS_COMMON/lab/view/BuildingLabScreenView' );
+  const FractionsCommonColorProfile = require( 'FRACTIONS_COMMON/common/view/FractionsCommonColorProfile' );
+  const fractionsMixedNumbers = require( 'FRACTIONS_MIXED_NUMBERS/fractionsMixedNumbers' );
+  const Screen = require( 'JOIST/Screen' );
 
   // strings
-  var screenLabString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.lab' );
-
-  /**
-   * @constructor
-   */
-  function LabScreen() {
-
-    var options = {
-      name: screenLabString,
-      backgroundColorProperty: FractionsCommonColorProfile.otherScreenBackgroundProperty
-    };
-
-    Screen.call( this,
-      function() { return new BuildingLabModel( true ); },
-      function( model ) { return new BuildingLabScreenView( model ); },
-      options
-    );
+  const screenLabString = require( 'string!FRACTIONS_MIXED_NUMBERS/screen.lab' );
+
+  class LabScreen extends Screen {
+    constructor() {
+      super(
+        () => new BuildingLabModel( true ),
+        model => new BuildingLabScreenView( model ),
+        {
+          name: screenLabString,
+          backgroundColorProperty: FractionsCommonColorProfile.otherScreenBackgroundProperty,
+          homeScreenIcon: BuildingLabScreenView.createMixedScreenIcon()
+        }
+      );
+    }
   }
 
-  fractionsMixedNumbers.register( 'LabScreen', LabScreen );
-
-  return inherit( Screen, LabScreen );
+  return fractionsMixedNumbers.register( 'LabScreen', LabScreen );
 } );