The current DJI go does not allow selection of P3 in its menu.
if you go to the support page for the Phantom 3 and downloads you can click the download for android and you will dl the go app from dji. just attach to pc and transfer the app to device and install. you will probably have to allow in settings to install from unknown sources.
Yes it is. Once opened you will see the Inspire drone. Swipe this picture to the left and it should take you through all the available selections.