I take the sd card out before I move things to the ext drive so it isn't confused on where to go.Before I did that, it was confused so didn't move anything. I don't use any special app just what came with the device and have had no problems moving stuff. However I move my kindle books, google play movies etc to the drive. The problem is which programs will let you move stuff from internal memory. Because kitkat won't let apps interact with others like in the past with the permissions, etc., some have not upgraded the apps to work around that. Before kitkat you couldn't move google movies to the external card or drive, now you can. That was my biggie so I am happy with how things are working now for the most part. I do wish android/google would realize that you need the ext card or drives to store stuff since they don't give you more memory. Not everyone can use their cloud based stuff as easily as others can so they need the cards/drives to compensate.