Ensembles 3 is here. 
A local-first sync framework for Core Data & SwiftData. No server, no cloud bill, no lock-in — your data syncs through services your users already have (iCloud, Dropbox, WebDAV…), or peer-to-peer.
I built it before the world moved to the cloud. It was almost end-of-life, but, lately, the world's been coming back around to local-first.
It's free to use with CloudKit and SwiftData/CoreData.
Ensembles — Sync for Swift Developers
The local-first sync framework for Core Data and SwiftData. Sync via iCloud, Dropbox, Google Drive, OneDrive, and more. No server required. No cloud costs. No lock-in.
(ensembles.io)