title: Android application as a service without activity
body: <p>I am making a set of apps and I have pretty much the same background service for all of them.</p>
  
  <p>I'm trying to make an app that has only this <code>Service</code>. so I don't repeat it in all of them, but the thing is don't need any <code>Activity</code>. because there is no UI needed for it, and so the user can't close it except if they stop the <code>Service</code>.</p>
  
  <p>I tried to remove the <code>Activity</code>, but then the app doesn't run or start.
  <strong>My question is: can I make an app exactly like <code>Google Play Services</code> so other apps can use its <code>Service</code>.</strong></p>
  
  <p>If yes than a snippet or a sample would be very welcome.</p>