New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  fields: [
  ],
  
  actions: {
    addField() {
      this.get('fields').pushObject({
        field_id: Math.random(),
        value: 'test'
      });
    },
    
    removeField() {
      this.get('fields').shiftObject();
    }
  }
});

templates.application.hbs

<button {{action "addField"}}>Add Field</button>
<button {{action "removeField"}}>Remove Field</button>

{{#each fields as |field|}}
<fieldset>
  <label for={{field.field_id}}>Label</label>
  {{input id=field.field_id value=field.value}}
  {{field.value}}
</fieldset>
{{/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"
  }
}