diff --git a/.gitignore b/.gitignore
index 7210ba6c..ae75970c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 node_modules/
-build/
+dist/
 release/
 npm-debug.log
 
diff --git a/README.md b/README.md
index 5e505a07..e40dbc20 100644
--- a/README.md
+++ b/README.md
@@ -50,10 +50,10 @@ Node.js is required to test this app.
 2. Run `npm install`.
 3. Run `npm start`.
 
-When you edit **.jsx** files, please execute `npm run build` before `npm start`.
+When you edit `src/**` files, please execute `npm run build` before `npm start`.
 
 ### Development
-#### `npm run serve`
+#### `npm run watch`
 Reload the app automatically when you have saved source codes.
 
 #### `npm test`
diff --git a/gulpfile.js b/gulpfile.js
index ad8bff8a..7cf0908e 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -3,16 +3,17 @@
 var gulp = require('gulp');
 var prettify = require('gulp-jsbeautifier');
 var babel = require('gulp-babel');
+var webpack = require('webpack-stream');
+var named = require('vinyl-named');
 var changed = require('gulp-changed');
 var esformatter = require('gulp-esformatter');
 var del = require('del');
 var electron = require('electron-connect').server.create({
-  path: './src'
+  path: './dist'
 });
 var packager = require('electron-packager');
 
 var sources = ['**/*.js', '**/*.css', '**/*.html', '!**/node_modules/**', '!**/build/**', '!release/**'];
-var app_root = 'src';
 
 gulp.task('prettify', ['prettify:sources', 'prettify:jsx']);
 
@@ -34,44 +35,112 @@ gulp.task('prettify:sources', ['sync-meta'], function() {
 });
 
 gulp.task('prettify:jsx', function() {
-  return gulp.src(app_root + '/**/*.jsx')
+  return gulp.src('src/browser/**/*.jsx')
     .pipe(esformatter({
       indent: {
         value: '  '
       },
       plugins: ['esformatter-jsx']
     }))
-    .pipe(gulp.dest(app_root));
+    .pipe(gulp.dest('src/browser'));
 });
 
-gulp.task('build', ['sync-meta', 'build:jsx']);
-
-gulp.task('build:jsx', function() {
-  return gulp.src(['src/browser/**/*.jsx', '!src/node_modules/**'])
-    .pipe(changed(app_root, {
-      extension: '.js'
-    }))
-    .pipe(babel({
-      presets: ['react']
-    }))
-    .pipe(gulp.dest('src/browser/build'));
+gulp.task('build', ['sync-meta', 'webpack', 'copy'], function() {
+  return gulp.src('src/package.json')
+    .pipe(gulp.dest('dist'));
 });
 
-gulp.task('serve', ['build'], function() {
+gulp.task('webpack', ['webpack:main', 'webpack:browser']);
+
+gulp.task('webpack:browser', function() {
+  return gulp.src('src/browser/**/*.jsx')
+    .pipe(named())
+    .pipe(webpack({
+      module: {
+        loaders: [{
+          test: /\.json$/,
+          loader: 'json'
+        }, {
+          test: /\.jsx$/,
+          loader: 'babel',
+          query: {
+            presets: ['react']
+          }
+        }]
+      },
+      output: {
+        filename: '[name].js'
+      },
+      node: {
+        __filename: false,
+        __dirname: false
+      },
+      target: 'electron'
+    }))
+    .pipe(gulp.dest('dist/browser/'));
+});
+
+gulp.task('webpack:main', function() {
+  return gulp.src('src/main.js')
+    .pipe(webpack({
+      module: {
+        loaders: [{
+          test: /\.json$/,
+          loader: 'json'
+        }]
+      },
+      output: {
+        filename: '[name].js'
+      },
+      node: {
+        __filename: false,
+        __dirname: false
+      },
+      target: 'electron'
+    }))
+    .pipe(gulp.dest('dist/'));
+});
+
+gulp.task('copy', ['copy:resources', 'copy:html/css', 'copy:webview:js', 'copy:modules']);
+
+gulp.task('copy:resources', function() {
+  return gulp.src('src/resources/**')
+    .pipe(gulp.dest('dist/resources'));
+});
+
+gulp.task('copy:html/css', function() {
+  return gulp.src(['src/browser/**/*.html', 'src/browser/**/*.css'])
+    .pipe(gulp.dest('dist/browser'));
+});
+
+gulp.task('copy:webview:js', function() {
+  return gulp.src(['src/browser/webview/**/*.js'])
+    .pipe(gulp.dest('dist/browser/webview'))
+});
+
+gulp.task('copy:modules', function() {
+  return gulp.src(['src/node_modules/bootstrap/dist/**'])
+    .pipe(gulp.dest('dist/browser/modules/bootstrap'))
+});
+
+gulp.task('watch', ['build'], function() {
   var options = ['--livereload'];
   electron.start(options);
-  gulp.watch(['src/**', '!src/browser/**', '!src/node_modules/**'], function() {
+
+  gulp.watch(['src/main.js', 'src/main/**/*.js', 'src/common/**/*.js'], ['webpack:main']);
+  gulp.watch(['src/browser/**/*.js', 'src/browser/**/*.jsx'], ['webpack:browser', 'copy:webview:js']);
+  gulp.watch(['src/browser/**/*.css', 'src/browser/**/*.html', 'src/resources/**/*.png'], ['copy']);
+
+  gulp.watch(['dist/main.js', 'dist/resources/**'], function() {
     electron.restart(options);
   });
-  gulp.watch('src/browser/**/*.jsx', ['build:jsx']);
-  gulp.watch(['src/browser/**', '!src/browser/**/*.jsx'], electron.reload);
-  gulp.watch('gulpfile.js', process.exit);
+  gulp.watch(['dist/browser/*.js'], electron.reload);
 });
 
 function makePackage(platform, arch, callback) {
   var packageJson = require('./src/package.json');
   packager({
-    dir: './' + app_root,
+    dir: './dist',
     name: packageJson.name,
     platform: platform,
     arch: arch,
diff --git a/package.json b/package.json
index 405d36bf..a5e317e2 100644
--- a/package.json
+++ b/package.json
@@ -9,8 +9,9 @@
     "install": "cd src && npm install",
     "postinstall": "npm run build",
     "build": "gulp build",
-    "start": "electron src",
-    "serve": "gulp serve",
+    "start": "electron dist",
+    "watch": "gulp watch",
+    "serve": "gulp watch",
     "test": "gulp build && mocha",
     "package": "gulp package",
     "package:windows": "gulp package:windows",
@@ -20,6 +21,8 @@
     "prettify": "gulp prettify"
   },
   "devDependencies": {
+    "babel-core": "^6.5.1",
+    "babel-loader": "^6.2.2",
     "babel-preset-react": "^6.3.13",
     "chromedriver": "^2.20.0",
     "del": "^2.2.0",
@@ -33,9 +36,13 @@
     "gulp-changed": "^1.3.0",
     "gulp-esformatter": "^5.0.0",
     "gulp-jsbeautifier": "^1.0.1",
+    "json-loader": "^0.5.4",
     "mocha": "^2.3.4",
     "mocha-circleci-reporter": "0.0.1",
     "should": "^8.0.1",
-    "webdriverio": "^3.3.0"
+    "style-loader": "^0.13.0",
+    "vinyl-named": "^1.1.0",
+    "webdriverio": "^3.3.0",
+    "webpack-stream": "^3.1.0"
   }
 }
diff --git a/src/browser/index.html b/src/browser/index.html
index c9c0a495..6df0c0b7 100644
--- a/src/browser/index.html
+++ b/src/browser/index.html
@@ -4,15 +4,12 @@
 <head>
   <meta charset="UTF-8">
   <title>electron-mattermost</title>
-  <script src="../node_modules/react/dist/react.min.js"></script>
-  <script src="../node_modules/react-dom/dist/react-dom.min.js"></script>
-  <script src="../node_modules/react-bootstrap/dist/react-bootstrap.min.js"></script>
-  <link rel="stylesheet" href="../node_modules/bootstrap/dist/css/bootstrap.min.css">
+  <link rel="stylesheet" href="modules/bootstrap/css/bootstrap.min.css">
 </head>
 
 <body>
   <div id="content"></div>
-  <script src="build/index.js"></script>
+  <script src="index.js"></script>
 </body>
 
 </html>
\ No newline at end of file
diff --git a/src/browser/index.jsx b/src/browser/index.jsx
index 726690fb..dc3324b3 100644
--- a/src/browser/index.jsx
+++ b/src/browser/index.jsx
@@ -1,5 +1,9 @@
 'use strict';
 
+const React = require('react');
+const ReactDOM = require('react-dom');
+const ReactBootstrap = require('react-bootstrap');
+
 const Grid = ReactBootstrap.Grid;
 const Row = ReactBootstrap.Row;
 const Col = ReactBootstrap.Col;
@@ -126,7 +130,7 @@ var MainPage = React.createClass({
       tabs_row = (
         <Row>
           <TabBar id="tabBar" teams={ this.props.teams } unreadCounts={ this.state.unreadCounts } mentionCounts={ this.state.mentionCounts } unreadAtActive={ this.state.unreadAtActive } mentionAtActiveCounts={ this.state.mentionAtActiveCounts }
-          activeKey={ this.state.key } onSelect={ this.handleSelect }></TabBar>
+            activeKey={ this.state.key } onSelect={ this.handleSelect }></TabBar>
         </Row>
       );
     }
@@ -296,24 +300,45 @@ window.addEventListener('contextmenu', function(e) {
   menu.popup(remote.getCurrentWindow());
 }, false);
 
+var showUnreadBadgeWindows = function(unreadCount, mentionCount) {
+  const badge = require('./js/badge');
+  const sendBadge = function(dataURL, description) {
+    // window.setOverlayIcon() does't work with NativeImage across remote boundaries.
+    // https://github.com/atom/electron/issues/4011
+    electron.ipcRenderer.send('win32-overlay', {
+      overlayDataURL: dataURL,
+      description: description
+    });
+  };
+
+  if (mentionCount > 0) {
+    const dataURL = badge.createDataURL(mentionCount.toString());
+    sendBadge(dataURL, 'You have unread mention (' + mentionCount + ')');
+  } else if (unreadCount > 0) {
+    const dataURL = badge.createDataURL('•');
+    sendBadge(dataURL, 'You have unread channels');
+  } else {
+    remote.getCurrentWindow().setOverlayIcon(null, '');
+  }
+}
+
+var showUnreadBadgeOSX = function(unreadCount, mentionCount) {
+  if (mentionCount > 0) {
+    remote.app.dock.setBadge(mentionCount.toString());
+  } else if (unreadCount > 0) {
+    remote.app.dock.setBadge('•');
+  } else {
+    remote.app.dock.setBadge('');
+  }
+}
+
 var showUnreadBadge = function(unreadCount, mentionCount) {
   switch (process.platform) {
     case 'win32':
-      var window = remote.getCurrentWindow();
-      if (unreadCount > 0 || mentionCount > 0) {
-        window.setOverlayIcon(path.join(__dirname, '../resources/badge.png'), 'You have unread channels.');
-      } else {
-        window.setOverlayIcon(null, '');
-      }
+      showUnreadBadgeWindows(unreadCount, mentionCount);
       break;
     case 'darwin':
-      if (mentionCount > 0) {
-        remote.app.dock.setBadge(mentionCount.toString());
-      } else if (mentionCount < unreadCount) {
-        remote.app.dock.setBadge('•');
-      } else {
-        remote.app.dock.setBadge('');
-      }
+      showUnreadBadgeOSX(unreadCount, mentionCount);
       break;
     default:
   }
diff --git a/src/browser/js/badge.js b/src/browser/js/badge.js
new file mode 100644
index 00000000..b77e1f22
--- /dev/null
+++ b/src/browser/js/badge.js
@@ -0,0 +1,29 @@
+'use strict';
+
+var createDataURL = function(text) {
+  const scale = 2; // should rely display dpi
+  const size = 16 * scale;
+  const canvas = document.createElement('canvas');
+  canvas.setAttribute('width', size);
+  canvas.setAttribute('height', size);
+  const ctx = canvas.getContext('2d');
+
+  // circle
+  ctx.fillStyle = "#FF1744"; // Material Red A400
+  ctx.beginPath();
+  ctx.arc(size / 2, size / 2, size / 2, 0, Math.PI * 2);
+  ctx.fill();
+
+  // text
+  ctx.fillStyle = "#ffffff"
+  ctx.textAlign = 'center';
+  ctx.textBaseline = 'middle';
+  ctx.font = (11 * scale) + "px sans-serif";
+  ctx.fillText(text, size / 2, size / 2, size);
+
+  return canvas.toDataURL();
+};
+
+module.exports = {
+  createDataURL: createDataURL
+};
diff --git a/src/browser/settings.html b/src/browser/settings.html
index f3b11678..f4ee24ef 100644
--- a/src/browser/settings.html
+++ b/src/browser/settings.html
@@ -4,15 +4,12 @@
 <head>
   <meta charset="UTF-8">
   <title>Settings</title>
-  <script src="../node_modules/react/dist/react.min.js"></script>
-  <script src="../node_modules/react-dom/dist/react-dom.min.js"></script>
-  <script src="../node_modules/react-bootstrap/dist/react-bootstrap.min.js"></script>
-  <link rel="stylesheet" href="../node_modules/bootstrap/dist/css/bootstrap.min.css">
+  <link rel="stylesheet" href="modules/bootstrap/css/bootstrap.min.css">
 </head>
 
 <body>
   <div id="content"></div>
-  <script src="build/settings.js"></script>
+  <script src="settings.js"></script>
 </body>
 
 </html>
\ No newline at end of file
diff --git a/src/browser/settings.jsx b/src/browser/settings.jsx
index 53d0319d..c25e53a8 100644
--- a/src/browser/settings.jsx
+++ b/src/browser/settings.jsx
@@ -3,6 +3,10 @@
 const remote = require('electron').remote;
 const settings = require('../common/settings');
 
+const React = require('react');
+const ReactDOM = require('react-dom');
+const ReactBootstrap = require('react-bootstrap');
+
 const Grid = ReactBootstrap.Grid;
 const Row = ReactBootstrap.Row;
 const Col = ReactBootstrap.Col;
@@ -12,6 +16,10 @@ const ListGroup = ReactBootstrap.ListGroup;
 const ListGroupItem = ReactBootstrap.ListGroupItem;
 const Glyphicon = ReactBootstrap.Glyphicon;
 
+function backToIndex() {
+  window.location = 'index.html';
+}
+
 var SettingsPage = React.createClass({
   getInitialState: function() {
     var config;
@@ -42,10 +50,10 @@ var SettingsPage = React.createClass({
       currentWindow.setAutoHideMenuBar(config.hideMenuBar);
       currentWindow.setMenuBarVisibility(!config.hideMenuBar);
     }
-    window.location = './index.html';
+    backToIndex();
   },
   handleCancel: function() {
-    window.location = './index.html';
+    backToIndex();
   },
   handleChangeHideMenuBar: function() {
     this.setState({
@@ -56,8 +64,8 @@ var SettingsPage = React.createClass({
     var teams_row = (
     <Row>
       <Col md={ 12 }>
-        <h2>Teams</h2>
-        <TeamList teams={ this.state.teams } onTeamsChange={ this.handleTeamsChange } />
+      <h2>Teams</h2>
+      <TeamList teams={ this.state.teams } onTeamsChange={ this.handleTeamsChange } />
       </Col>
     </Row>
     );
@@ -69,8 +77,8 @@ var SettingsPage = React.createClass({
     var options_row = (options.length > 0) ? (
       <Row>
         <Col md={ 12 }>
-          <h2>Options</h2>
-          { options }
+        <h2>Options</h2>
+        { options }
         </Col>
       </Row>
       ) : null;
@@ -81,9 +89,9 @@ var SettingsPage = React.createClass({
         { options_row }
         <Row>
           <Col md={ 12 }>
-            <Button id="btnCancel" onClick={ this.handleCancel }>Cancel</Button>
-            { ' ' }
-            <Button id="btnSave" bsStyle="primary" onClick={ this.handleSave } disabled={ this.state.teams.length === 0 }>Save</Button>
+          <Button id="btnCancel" onClick={ this.handleCancel }>Cancel</Button>
+          { ' ' }
+          <Button id="btnSave" bsStyle="primary" onClick={ this.handleSave } disabled={ this.state.teams.length === 0 }>Save</Button>
           </Col>
         </Row>
       </Grid>
diff --git a/src/main.js b/src/main.js
index af10de33..8df87f72 100644
--- a/src/main.js
+++ b/src/main.js
@@ -7,9 +7,10 @@ const Menu = electron.Menu;
 const Tray = electron.Tray;
 const ipc = electron.ipcMain;
 const fs = require('fs');
+const path = require('path');
 
 var settings = require('./common/settings');
-var appMenu = require('./menus/app');
+var appMenu = require('./main/menus/app');
 
 var argv = require('yargs').argv;
 
@@ -38,6 +39,7 @@ try {
   }
 }
 catch (e) {
+  config = settings.loadDefault();
   console.log('Failed to read or upgrade config.json');
 }
 
@@ -81,11 +83,11 @@ app.on('before-quit', function() {
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.
 app.on('ready', function() {
-  // set up tray icon to show balloon
   if (process.platform === 'win32') {
-    trayIcon = new Tray(__dirname + '/resources/tray.png');
+    // set up tray icon to show balloon
+    trayIcon = new Tray(path.resolve(__dirname, 'resources/tray.png'));
     trayIcon.setToolTip(app.getName());
-    var tray_menu = require('./menus/tray').createDefault();
+    var tray_menu = require('./main/menus/tray').createDefault();
     trayIcon.setContextMenu(tray_menu);
     trayIcon.on('click', function() {
       mainWindow.focus();
@@ -95,11 +97,17 @@ app.on('ready', function() {
     });
     ipc.on('notified', function(event, arg) {
       trayIcon.displayBalloon({
-        icon: __dirname + '/resources/appicon.png',
+        icon: path.resolve(__dirname, 'resources/appicon.png'),
         title: arg.title,
         content: arg.options.body
       });
     });
+
+    // Set overlay icon from dataURL
+    ipc.on('win32-overlay', function(event, arg) {
+      var overlay = electron.nativeImage.createFromDataURL(arg.overlayDataURL);
+      mainWindow.setOverlayIcon(overlay, arg.description);
+    });
   }
 
   // Create the browser window.
@@ -112,7 +120,7 @@ app.on('ready', function() {
     // follow Electron's defaults
     window_options = {};
   }
-  window_options.icon = __dirname + '/resources/appicon.png';
+  window_options.icon = path.resolve(__dirname, 'resources/appicon.png');
   mainWindow = new BrowserWindow(window_options);
   if (window_options.maximized) {
     mainWindow.maximize();
diff --git a/src/menus/app.js b/src/main/menus/app.js
similarity index 97%
rename from src/menus/app.js
rename to src/main/menus/app.js
index 2759d6ba..68fdb8a4 100644
--- a/src/menus/app.js
+++ b/src/main/menus/app.js
@@ -15,7 +15,7 @@ var createTemplate = function(mainWindow) {
     }, {
       label: 'Settings',
       click: function(item, focusedWindow) {
-        mainWindow.loadURL('file://' + __dirname + '/../browser/settings.html');
+        mainWindow.loadURL('file://' + __dirname + '/browser/settings.html');
       }
     }, {
       label: 'Quit',
diff --git a/src/menus/tray.js b/src/main/menus/tray.js
similarity index 100%
rename from src/menus/tray.js
rename to src/main/menus/tray.js
diff --git a/src/resources/badge.png b/src/resources/badge.png
deleted file mode 100644
index dfc56224..00000000
Binary files a/src/resources/badge.png and /dev/null differ
diff --git a/test/browser_test.js b/test/browser_test.js
index 746ce496..a30ae701 100644
--- a/test/browser_test.js
+++ b/test/browser_test.js
@@ -25,7 +25,7 @@ var options = {
     browserName: 'chrome',
     chromeOptions: {
       binary: electron_binary_path, // Path to your Electron binary.
-      args: ['app=' + path.join(source_root_dir, 'src'), '--config-file=' + config_file_path] // Optional, perhaps 'app=' + /path/to/your/app/
+      args: ['app=' + path.join(source_root_dir, 'dist'), '--config-file=' + config_file_path] // Optional, perhaps 'app=' + /path/to/your/app/
     }
   }
 };
@@ -187,7 +187,7 @@ describe('electron-mattermost', function() {
     it('should show index.thml when Cancel button is clicked', function() {
       return client
         .init()
-        .url('file://' + path.join(source_root_dir, 'src/browser/settings.html'))
+        .url('file://' + path.join(source_root_dir, 'dist/browser/settings.html'))
         .waitForExist('#btnCancel')
         .click('#btnCancel')
         .pause(1000)
@@ -201,7 +201,7 @@ describe('electron-mattermost', function() {
     it('should show index.thml when Save button is clicked', function() {
       return client
         .init()
-        .url('file://' + path.join(source_root_dir, 'src/browser/settings.html'))
+        .url('file://' + path.join(source_root_dir, 'dist/browser/settings.html'))
         .waitForExist('#btnSave')
         .click('#btnSave')
         .pause(1000)