Appengine authentication on Android

Question

I have a Python App Engine application where a user can log in using foursquare, then they must log in using Hunch. This all works fine but now I am trying to allow the user to authenticate on the android device. I don't want the user to have to log in to both 4sq & hunch on the phone so I want them to be able to authenticate with my backend and from there this would log on on their behalf. Is there anywhere where I could find tutorials on something like this? Should I create a custom authentication on my app or allow the user to sign on using their Google Account?

Answer 1

If they've already authenticated with your app, and set up oauth tokens with foursquare and Hunch, you can use this pattern to authenticate with your app.

There's no way to authenticate 'on their behalf' with your app short of asking the user for their credentials. If there were, any app would be able to impersonate you to any service you use.