I have an app where ideally I have sync between web, mobile, and watchos. Firestore (firebase) works well for sync between web and mobile. But I'm a bit stuck as to the best option for watchOS. WatchOS doesn't support firestore, but even if it does, I think many apple watches don't have internet support so I want an option based on watchconnectivity. I use watchconnectivity to send the data, but just store it in @State. When I kill the watchOS app, the state goes away, even though I'd rather it persist. What is the best option to persist it ? Is it CoreData, AppStore, or some other option? CoreData seems like the most reliable option, but also a lot of extra code to keep the watchOS coreData synced with the firestore app. Wanted to post here in case anyone has any insights. I have some apps on my watch that seem to sync with their iOS companion apps without much problems, even if I turn off the iphone and kill the watchOS app, when I restart the watchOS app, the basic state persists. So these devs are doing something - is it just coredata? appstorage? or something else. Wanted to post here in case any good ideas.
Best sync option for watchOS / SwiftUI?
There are a variety of options available for data communication for Apple Watch. Determining which is the best for your particular app depends on the nature of the data and the app. This WWDC session might help give you some idea which ones are suited to which types of data and apps: There and back again: Data transfer on Apple Watch.. This could also help clarify the connectivity of Apple Watch in general for you.
Your data storage options are similarly specific to the type of data and the nature of the app. It is going to depend on how much data, how you want to access the data, and a variety of other factors. It could even be related to how you decide to synchronize the data. Also think about how much data will be useful for people in your Watch app.