Abraham, I took the ADB suggested in that article and copied it into my Commands for App Inventor folder and then tried from there. Gave me the same result (USB not connected, although it gave me a couple of seconds of hoping it would work).
I ignored the option to use the custom android SDK tools as I could see no way to retrieve such a file as shown.
Got the advice from another post that you uploaded.
I now fancy getting this Genymotion working and using in school with all pupils. Sooo frustrating when things don't go as expected!