New Twiddle

application.controller.js

import Ember from 'ember';

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

application.template.hbs

<h1>Sticky Scroller</h1>
<br>
<br>
{{sticky-scroller}}
<br>
<br>

sticky-scroller.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  attributeBindings: ['style'],
  style: "border: solid; overflow:auto; max-height: 500px;",
  
  _scrollTop: 0,
  
  didInsertElement() {
    this._super(...arguments);
 		this.$().on('scroll', Ember.run.bind(this, this._didScroll)); 
  },
  
  willDestroyElement() {
		this._super(...arguments);
    this.$().off('scroll');
  },
  
  _didScroll() {
  	const scrollTop = Math.round(this.element.scrollTop);
    console.log(scrollTop);
    Ember.set(this, '_scrollTop', scrollTop);
    
    if (this.$('.floater').css('position').indexOf('sticky') !== -1) {
    	this.$('.floater').css({
        'position': 'relative',
        'top': scrollTop + 'px'
      });
    }
  }
});

sticky-scroller.template.hbs

<div class="overflow" style="min-height:5000px;">
	<div class="floater" style="position: relative; top:{{{_scrollTop}}}px;">
    <h4>I stay put when you scroll.</h4>
  </div>
</div>

styles.app.css

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

div {
	border: solid;  
}

.floater {
  position: sticky;
  top: 4px;
}

twiddle.json

{
  "version": "0.4.17",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}