On my Galaxy Nexus running 4.2.1, I see two Settings apps in Settings > Apps. One is name Settings (28KB) and the other is Settings Storage (520KB). Both have the version 4.2.1-533553. Is the storage one for handling the Settings > Storage screen? If so why is there a separate app for that? If not, what is it for?
Settings Storage, technically speaking, is actually an internal app that manages the content provider framework for Settings itself. It also registers itself upon Android boot-up.
The Settings storage backing data store handler, really, uses an Sqlite database, which is in the public domain and free to use.
This database is required to hold the settings for updating and retrieval via the Setting's internal content provider, which is integrated through-out the ROM in itself, so everything that is seen through Menu > Settings, "talk" to the content provider" and that in itself, handles the backing store.
Also, that Settings own content provider is actually global through-out the ROM, irrespective of Android version, so that the system apps and user apps can use that to check on it by querying it and act accordingly.
Hence the "seeing of two Settings apps"....