We need to put a sticky at the top of this thread so the same questions stopped getting repeated.
In it's current state, the Hotwire app will only support Android version 3.1 to 4.1.2
This is not a issue with the App itself, it is a issue with Android. When versions above 4.1.2 were released, USB was disabled.
When version 4.4 is released, it is " supposed " to be re-enabled.
Also, future versions of the Hotwire App will support Gen 1 ESC's, this has been confirmed by the President of Tekin in this very thread.