swift - Shared values across all devices? -

i have app i'd configurations modified in web backend.

my initial thought store default values in plist file, request updated values remote server via json. don't because it's asynchronous, updates in web admin not instant, if user kills app , reopens (some configurations needed such changing global tint.

another idea had if mobile devices use shared file in icloud. possible users who've downloaded app access same file synchronously in cloud? or core data have shared area devices read example?

any ideas or experiences on how handle i'm trying accomplish? advice or insight.

if have data want share users of app, use public database in cloudkit. asynchronous, can subscribe users receive changes once available.