Plugins for PhoneGap build are defined in config.xml. http://docs.build.phonegap.com/en_US/configuring_plugins.md.html#Plugins
<gap:plugin name="phonegap-nfc" source="npm" />
Use the phonegap
command to upload the project to the PhoneGap Build servers
phonegap remote build android
Login to http://build.phongap.com to download the app to your phone.