New Twiddle

controllers.application.js

import Ember from 'ember';
const { Controller, inject } = Ember;

export default Controller.extend({
  display: inject.service(),
  
  actions: {
  	toggle() {
    	this.get('display').toggleVisibility();
    }
  }
});

services.display.js

import Ember from 'ember';
const { Service } = Ember;

export default Service.extend({
  isThingVisible: false,
  
  toggleVisibility() {
    this.toggleProperty('isThingVisible');
    console.log(this.get('isThingVisible'));
  },
  
  actions: {
    toggleVisibility() { 
      return this.toggleVisibility(...arguments);
    }
  }
});

templates.application.hbs

<button {{action "toggle"}}>
	Toggle Visibility (controller action)
</button>

<button {{action "toggleVisibility" target=display}}>
	Toggle Visibility (service method - element action)
</button>

<button onclick={{action "toggleVisibility" target=display}}>
	Toggle Visibility (service method - closure action)
</button>

<p>isThingVisible: {{display.isThingVisible}}</p>

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": "2.14.0",
    "ember-template-compiler": "2.14.0",
    "ember-testing": "2.14.0"
  }
}