I\'m starting to write an app whereby a mobile app (Android/IPhone) will communicate with the GAE backend (Python) through a series of Web API calls using JSON.
I can\'t
Try gae-sessions for session management. It creates secure cookies for you and allows you to easily associate data with each user. Just provide your own logic for the initial authentication.
It was built specifically for App Engine and is pretty popular and super fast/scalable.
https://github.com/dound/gae-sessions