New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  animals: [
    {
      name: 'Cat',
      visible: true
    },
    {
      name: 'Dog',
      visible: false
    },
    {
      name: 'Cow',
      visible: true
    }
  ]
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Items in loop (Animals):
<br>
<br/>

{{#each animals as |item|}}
  {{#if item.visible}}
     <b>{{item.name}} is visible!</b>
  {{/if}}
  <br/>
  <button onclick={{action (mut item.visible) (if item.visible false true)}}>{{if item.visible 'Hide' 'Show'}} {{item.name}}</button>
  <br/>
{{/each}}
<br>

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"
  }
}