title: Branch.io implement referral system
body: <p>I'm trying to implement branch.io referral system in my game.</p>
  
  <p>I have some questions about branch.io</p>
  
  <ol>
  <li>It is mandatory to  identify users on log in and log out, or if I don't want branch system will take care of this?</li>
  <li>Before rewarding user in <code>onStateChanged</code> every time I need to check <code>changed</code> to be <code>true</code> ?</li>
  <li>It is mandatory to set credits balance(on first start) and then use <code>redeemRewards</code> ?</li>
  <li>How to implement own Filter after adding in reward rule and filter in dashboard  ?</li>
  </ol>
  
  <p>My problem is that <code>onStateChanged</code> call me every time and on every device(referring and referred acting users), even my rule in dashboard is only  <code>Referred acting user</code> and even I add custom filter in dashboard </p>