Apple iCloud+: Apple’s family cloud — photos, files, and device backup with Family Sharing, and optional Advanced Data Protection for end-to-end encryption. (Deeply integrated on Apple devices; limited web + Windows access · iCloud+ ~$0.99–$9.99/mo by storage, shareable across Family Sharing)
Cornerstone: A private operating system for the home: a family AI you can actually ask things, an encrypted vault for photos and documents that only you can open, age-graded kid access with parent oversight, a device mesh, and encrypted cold backup — all under one rule, honest custody: the server holds only ciphertext and refuses to receive your key.
✓ Beautifully integrated and effortless on Apple hardware
✓ Advanced Data Protection now offers end-to-end encryption for most iCloud categories
✓ Superb photo library, device backup, and Family Sharing
✓ Enormous scale and reliability
Where Cornerstone differs
→ Apple-first — Cornerstone is cross-platform and doesn’t lock your family’s data to one vendor
→ No family AI you can ask; iCloud is storage + sync, not an assistant
→ ADP is opt-in and Apple-defined; Cornerstone’s design is custody-by-default with a "what the server sees" proof panel
→ No self-host path — your data lives on Apple’s terms
Pick Apple iCloud+ if…
• Your family is all-in on Apple devices
• You want the most seamless photos + backup experience with no setup
• Turning on Advanced Data Protection covers your privacy needs
Pick Cornerstone if…
• Your family spans Apple, Android, Windows, and you don’t want lock-in
• You want a private family AI, not just storage
• You want to be able to verify — and eventually self-host — what holds your data
Where we’re honestly behind
– Cornerstone is NEW — Proton and Apple are mature, audited, and battle-tested. If you want proven-today encryption from an established vendor, pick them, honestly
– Parts of the vision — the full device mesh, managed cold backup, self-host — are early or still being built
– No decade-deep photo library or app ecosystem yet; the depth of iteration isn’t there
– Own-family-first: this is being built for real use before it’s a polished mass-market product