And for a specific example of the sort of ecosystem stuff I am talking about, to save/load some local data on iOS you have some API options: Core Data SQLite

And for a specific example of the sort of ecosystem stuff I am talking about, to save/load some local data on iOS you have some API options: Core Data SQLite NSArchiver NSKeyedArchiver NSUserDefaults JSON Property lists Protocol buffers stdio NSData memory-mapped files Realm This is without getting into anything too obscure. This list is probably also out of date.