Warranty or Refresh, if its a fault caused by Litchi then it would not be covered, not sure i have ever seen this. Have seen plenty of destroyed drones caused by operator error using Litchi, but not as many as using DJI Go. If you send the bird in they can tell if it was a parts failure that was the cause no matter what app you are using, if it was then its covered by warranty, if it wasn't a part failure covered under Warranty then it could be covered under Refresh. The problem comes if you don't have the bird to send in. In that case they can't read any info so you are out of luck 99% of the time, even if you are using DJI Go. Even Refresh won't won't cover you if you don't have the bird to send in.