title: how to draw over other apps in flutter?
body: <p>I want to <strong>show alert box or pop up even my flutter app is closed</strong>. similar to this picture</p>
  
  <p><a href="https://i.stack.imgur.com/lcUGY.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/lcUGY.jpg" alt="enter image description here"></a></p>