I've noticed some apps like Foursquare and Quiz up automatically recover the user session after the apps are uninstalled and reinstalled, I'm wondering what is the common approach to achieve this, is the user session saved using iCloud?
Any hints on this are appreciated.
Thanks
The user session information is saved in the keychain. This securely protects the data (or at least as much as is generally accepted) and the keychain is not deleted when an app is deleted.