Click this link for a video on installing the app update:
https://www.youtube.com/watch?v=jH_oou_0NH8&index=5&list=PL9GxcpnVuIG9p2HGyNxZwKc4zu075pDj-
Downloaded the update, couldn't be any easier. My GP 35 runs quieter and low speed improved.
Last night I updated my two locos (an FT & Rs3) along with a third loco belonging to a friend (a GP 35), and it went just as it was supposed to. All locos are now quieter and seem smoother, too. I really like this system's simplicity a lot better than all the complications of DCC!
Bill in FtL