makes the app a single instance application

src/electron/window-manager.js

@@ -23,7 +23,7 @@ var RESOURCES = path.resolve(__dirname, '../../');
 var DEFAULT_URL = 'file://' + path.join(RESOURCES, 'index.html#connect');
 
 /**
- * We want want the Connect dialog window to be special
+ * We want the Connect dialog window to be special
  * and for there to ever only be one instance of it
  * so we'll use scope to essentially make it a Singleton.
  */
@@ -62,6 +62,23 @@ module.exports.create = function(opts) {
       'direct-write': true
     }
   });
+
+  // makes the application a single instance application
+  // see "app.makeSingleInstance" in https://github.com/atom/electron/blob/master/docs/api/app.md
+  var shouldQuit = app.makeSingleInstance(function(commandLine, workingDirectory) {
+  // Someone tried to run a second instance, we should focus our window
+    if (_window) {
+      if (_window.isMinimized()) _window.restore();
+      _window.focus();
+    }
+    return true;
+  });
+
+  if (shouldQuit) {
+    app.quit();
+    return;
+  }
+
   attachMenu(_window);
   _window.loadUrl(opts.url);