electron-builder: Error: Cannot find module ... app.asar/index.js

Successfully built my angular1 app as an electron app. I can run it using electron-prebuilt, however, when I launch the installed dmg, the app fails immediately.

Image contains error message:

my dev-level package.json:

{
    "name": "activity-frontend",
    "version": "1.1.1",
    "author": "Sante Kotturi",
    "description": "activity-frontend: An Ionic project",
    "dependencies": {
        "gulp": "^3.5.6",
        "gulp-concat": "^2.2.0",
        "gulp-minify-css": "^0.3.0",
        "gulp-rename": "^1.2.0",
        "gulp-sass": "^2.0.4"
    },
    "devDependencies": {
        "bower": "^1.3.3",
        "electron-builder": "^3.5.0",
        "electron-prebuilt": "^0.37.5",
        "gulp-util": "^2.2.14",
        "shelljs": "^0.3.0"
    },
    "scripts": {
        "electron": "electron www",
        "postinstall": "install-app-deps",
        "pack": "build",
        "dist": "build"
    },
    "build": {
        "osx": {
            "contents": [
                {
                    "x": 410,
                    "y": 220,
                    "type": "link",
                    "path": "/Applications"
                },
                {
                    "x": 130,
                    "y": 220,
                    "type": "file"
                }
            ]
        }
    }
}

my app-level package.json which specifies a main.js:

{
  "name"    : "activity-uploader",
  "version" : "0.0.1",
  "main"    : "main.js"
}

my main.js just in case it helps: [EDIT with correct main.js]

var app = require('app');  // Module to control application life.
var BrowserWindow = require('browser-window');  // Module to create native browser window.

// Report crashes to our server.
require('crash-reporter').start();

// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is GCed.
var mainWindow = null;

// Quit when all windows are closed.
app.on('window-all-closed', function() {
  // On OS X it is common for applications and their menu bar
  // to stay active until the user quits explicitly with Cmd + Q
  if (process.platform != 'darwin') {
    app.quit();
  }
});

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
app.on('ready', function() {
  // Create the browser window.
  mainWindow = new BrowserWindow({width: 800, height: 700});

  // and load the index.html of the app.
  mainWindow.loadURL('file://' + __dirname + '/index.html');

  // Emitted when the window is closed.
  mainWindow.on('closed', function() {
    // Dereference the window object, usually you would store windows
    // in an array if your app supports multi windows, this is the time
    // when you should delete the corresponding element.
    mainWindow = null;
  });
});

I launched Mac Finder > my app > Contents > Resources to see if app.asar was an inspectable but its a binary file: app.asar: application/octet-stream; charset=binary

Any help or pointing in the right directions of resources is much appreciated.