Life of Twitter tokens in iOS Settings


Hi, we have recently released an iOS app leveraging Twitter authentication. On iOS5+ we are attempting to authenticate via the Twitter credentials in the iOS Settings. We don’t have a fall back to authenticate via Twitter in Safari if this fails (yet).

My question is around the life of the Twitter tokens stored in Settings. We have seen that users who continue to use the native iOS Twitter app on the device may have expired Twitter tokens in Settings when our app tries to authenticate against them.

I would have assumed that using the Twitter app on iOS would regularly refresh the Twitter tokens in the iOS Settings. Does anyone have any info on why tokens might expire in Settings if the user continues to use the twitter app?