title: achieve same layout on android & iOS Titanium
body: <p>i'm creating an ios,android app using titanium so i positioning my ui view on specific percentage from screen size using <code>platformWidth</code> and <code>platformHeight</code> multiplied by a number 
  e.g. <code>0.5*platformHeight</code> for the middle of the screen and every thing work on all iOS devices sizes.<br>
  but on android devices this value became too large </p>
  
  <pre><code>Note i m using "dp" as a default unit 
  </code></pre>
  
  <p>so any idea on how to achieve same layout in this way </p>