No APNs library can work on the Google App Engine. If running from GAE, you might want to check Urban Airship.
The real issue here is that the APNs protocol requires opening a direct TCP socket connection with a custom non-HTTP protocol. GAE doesn't support that.
This are known reported issues:
- http://code.google.com/p/googleappengine/issues/detail?id=347 -- Adding socket support
- http://code.google.com/p/googleappengine/issues/detail?id=1164 -- Adding support for Apple Push Notification Service
Regards,- Mahmood