LOL so apparently ol' Stevie J-to-the-S hated that users needed to understand what a file is.
So for iOS, Apple attempted to get rid of the concept entirely.
But since this is, of course, not really possible, engineers faked the total abstraction of the file system by storing the actual location of, ya know, *files* (double LOL) in.......
=>> a SQLite database
(!!!)
Really just SOLID thinking.
This SQLite waypoint applies as much to system and application files, as to data.
So, in summary, to run an app on iOS, you need to go through SQLite.