by Juan Leyva.
Hi Daniel,
are you creating a mobile app based on Moodle Mobile from scratch? If you are using the current Moodle Mobile app code the only thing you should do is edit the config.json file and change there the gcmpn (GCM project number):
https://github.com/moodlehq/moodlemobile/blob/master/config.json
In Airnotifier you should monitor the error log to see what is happening, how do you start Airnotifier?
Airnotifier has a supervisord config file, you can use supervisord for starting/monitoring the server https://github.com/airnotifier/airnotifier/blob/master/supervisord.conf-sample
Cheers, Juan