title: How to draw a state diagram, and which drawing software or online drawing website can I use?
body: <p>How can I  draw  a picture  like this :</p>
  
  <p><a href="http://developer.android.com/images/activity_lifecycle.png" rel="nofollow">http://developer.android.com/images/activity_lifecycle.png</a></p>
  
  <p>Does the marker of this picture use some kind of software from an online drawing picture website?</p>
  
  <p>Because of the appearance, I don't think this picture is created by yEd, visio and XMind. </p>