New Twiddle

components.todo-grid.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'todo-item',
  classNames: ['todo-item'],
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Contact List'
});

models.todo.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  desc: attr('string'),
  todo: attr('boolean'),
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
  	return [{
    	desc: 'Pick up the laundry',
      done: false,
    }];
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.todo-item {
  display: flex;
  align-items: center;
  background: #f5f5f5;
  border-top: 1px solid #cdcdcd;
  border-bottom: 1px solid #cdcdcd;
  padding: 0.5rem;
}

.todo-checkbox {
	margin-right: 1rem;
}

templates.application.hbs

<h4>Welcome to {{appName}} djd</h4>
	{{todo-grid model=model}}
	{{outlet}}

templates.components.todo-grid.hbs

{{#each model as |todo| }}
	<input type="checkbox" checked={{todo.done}} class="todo-checkbox"/> {{todo.desc}}
{{/each}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}