Android SharedPreferences with MODE_PRIVATE,MODE_WORLD_READABLE,MODE_WORLD_WRITABLE

getSharedPreferences(String name, int mode) is explained here

MODE_PRIVATE: File creation mode: the default mode, where the created file can only be accessed by the calling application (or all applications sharing the same user ID).

MODE_WORLD_READABLE: File creation mode: allow all other applications to have read access to the created file.

MODE_WORLD_WRITEABLE : File creation mode: allow all other applications to have write access to the created file.

More info here

Edit
As of API 17, the MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE are deprecated:

This constant was deprecated in API level 17.
Creating world-readable files is very dangerous, and likely to cause security holes in applications. It is strongly discouraged; instead, applications should use more formal mechanism for interactions such as ContentProvider, BroadcastReceiver, and Service. There are no guarantees that this access mode will remain on a file, such as when it goes through a backup and restore.