title: Transparent overlay in React Native
body: <p>I'm trying to get a transparent overlay sliding down in an app, pretty much like this here (all/filter-by):</p>
  
  <p><img src="https://i.stack.imgur.com/lJdpZ.gif" alt="transparent slider"></p>
  
  <p>So far I found react-native-slider and react-native-overlay. I modified the slider to work from top to bottom, but it always moves down the ListView as well. If using react-native-overlay, the overlay is static and I can't move it.</p>
  
  <p>I added some demo code from the original react-native tutorial <a href="https://gist.github.com/PatrickHeneise/24c400226fc80df2749e" rel="noreferrer">in this gist</a>. When clicking the button, the content should stick, and the menu should overlay. The transparency is not that important right now but would be awesome.</p>
  
  <p>What would be the smartest solution?</p>