New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  properties: Ember.A([
    Ember.Object.create({ name: '', isFocused: true })
  ]),
  
  actions: {
    addProperty(name) {
      const property = this.get('properties').findBy('isFocused', true)
      property.setProperties({
        name: name,
        isFocused: false
      })
      this.get('properties').addObject(Ember.Object.create({
        name: '', 
        isFocused: true
      }))
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{#each properties as |property|}}
	{{my-component 
  	isFocused=property.isFocused
    onEnter=(action 'addProperty')
  }}
{{/each}}
<br>
<br>

templates.components.my-component.hbs

{{#if isFocused}}
  {{input 
  	type='text' 
    value=name
    enter=(action onEnter name)
   }}
{{else}}
  {{name}}
{{/if}}

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}