So what cruft hangs around when you delete an iOS app? ...

[cmeisenzahl]

You know how on Windows when you uninstall an app, the system is never really the same again? There are often still .ini files, registry entries, even folders still around. Not a huge deal, but mildly annoying and can make a mess over time. I think OS X is better about this, but not perfect.

I've been under the impression that when you delete/uninstall an iOS app, it's really gone. No misc. debris hanging around.

But over the weekend I reinstalled the Facebook app after having deleted it a few weeks earlier. When I launched it it asked me if I was the same previous user, and authenticated me, no password required. So did the FB app leave some info around on my phone from before? Or did the FB servers recognize me by a unique ID on my phone? Some other third scenario?

Thanks in advance

 

[pmau]

When you delete an App, the whole sandbox container will be deleted.
When you re-insatll an App and you have iCloud Backup, all data belonging to the App is restored.

As for the password, it's stored in the system-wide keychain.
Passwords and secure data do not belong to the App itself.
You can create secure files that are not part of the App Container.

 

[cmeisenzahl]

When you delete an App, the whole sandbox container will be deleted.
When you re-insatll an App and you have iCloud Backup, all data belonging to the App is restored.

As for the password, it's stored in the system-wide keychain.
Passwords and secure data do not belong to the App itself.
You can create secure files that are not part of the App Container.

Ahh, that helps. Thanks.