With CloudKit, Apple provide an effective, simple, and secure mechanism to synchronise user data between devices. The developer APIs are easy to use, and it’s accounted against users' iCloud storage, making it an affordable way for developers to build robust synchronised apps.

Unfortunately, CloudKit is only available on Apple devices, requires that data is stored on Apple serves, and significantly contributes to lock-in. Every new CloudKit app makes it harder for users to choose a new platform. The centralised architecture also requires always-on internet—without it, data on a user’s device will diverge quickly leading, at best, to confusion and, at worst, confusing synchronisation conflicts and data loss.

I propose a cross-platform, peer-to-peer alternative to CloudKit—let us call it everywhered—that offers application developers an easy-to-use synchronisation platform, and users, a lock-in-free and efficient way to share data across all their devices. Ideally such a solution would work with point-to-point networking to avoid the need for all devices to be connected to a common local network.