title: How can I display text or graph in a Service, without an Activity?
body: <p>I have a <code>Service</code> which with <code>BroadcastReceiver</code>, and want to display text when it gets some messages.</p>
  
  <p>This <code>Service</code> is similar to TV remote control, so I don't want to use Notification or Toast. I want to show inputted digits in the right-top corner, just as the traditional TV.</p>
  
  <p><a href="https://play.google.com/store/apps/details?id=com.ckideas.networkmeter" rel="nofollow">Network Meter</a> can draw network speed graph in background, so this should be technically possible. However, I don't know how to start.</p>
  
  <p>Any help is appreciable. Thank you!</p>