Settings serves as a wrapper for
NSUserDefaults, a persistent key-value store available only on iOS.
watchId is the number returned by
watchKeys() when the subscription was originally configured.
Get the current value for a given
Set one or more values in
Subscribe to be notified when the value for any of the keys specified by the
keys parameter has been changed in
NSUserDefaults. Returns a
watchId number that may be used with
clearWatch() to unsubscribe.
watchKeys()by design ignores internal
set()calls and fires callback only on changes preformed outside of React Native code.