The http://www.waleedkhan.com/simple-gps-app-with-phonegap/ tutorial has been followed to create this firefox os app.
cordova create mysimplegps
cordova platform add firefoxos
cordova prepare firefoxos
And then I copied index, code and arrow files from the website to www/...
To create the apk: simpleGPS/platforms/firefoxos/www$ mozilla-apk-cli ./ ./simpleGPS.apk