Skykeep is a free, open-source application suite written in Rust and licensed under GPL-3.0 that brings Apple's iCloud services to non-Apple operating systems.

The main features and capabilities of Skykeep include:

• Native App Suite & Cross-Platform Sync: Provides six standalone applications—Notes, Reminders, Calendar, Contacts, iCloud Drive, and Photos—that run as native software on Windows, Linux, and Android while keeping data in sync with iPhone, iPad, and Mac devices.

• Offline-First & Local Storage: Reads all app screens directly from a local SQLite library so every app opens instantly and functions offline. Edits appear immediately and are queued in an outbox to be sent in order when back online.

• Rust & Tauri Architecture: Built around a native Rust engine paired with a lightweight Tauri frontend window on desktop, idling at under 0.1% of a CPU core.

• Privacy-First & Secure Sign-In: Directs all traffic strictly between your local device and Apple's servers without using intermediate Skykeep servers, accounts, or analytics. Rebuilds Apple's SRP (Secure Remote Password) protocol with two-factor authentication in Rust, saving credentials inside your local system keyring.

• Advanced Sync & Local Backups: Merges note edits using Apple's Conflict-free Replicated Data Type (CRDT), backs up full-resolution photos, videos, and drive contents to a chosen local folder, and integrates iCloud Drive and Photos as real folders inside desktop file managers.