Nudii is a virtual nudibranch sea slug powered by AI that runs entirely on your iPhone. No servers. No subscription to start. No data ever leaving your device.
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Nudii runs a 2.3 billion parameter AI model entirely on your device. No cloud servers. No data collection. No account needed. What you share with your nudii stays with your nudii.
Features
Built on real marine biology and real on-device AI — not a chatbot with a cute skin.
Powered by Google's Gemma model running entirely on your iPhone 15 Pro or later. Your conversations are never sent anywhere — not to us, not to anyone.
Your nudii remembers what you've talked about and brings it up naturally. It builds a real picture of your life over time — all stored locally on your phone.
Five life stages over roughly a year — Egg, Veliger, Juvenile, Adult, Mythic. Each stage has its own personality, voice, and look. Mythic must be earned; it can't be bought.
About once a week, your nudii enters a special mood — Philosophical, Extra Playful, Mysteriously Quiet, or Glowing. It changes every interaction for that full day.
Feed it, clean it, put it to sleep, play four retro mini-games with it. Real-world steps and workouts via HealthKit earn your nudii bonuses.
Every nudibranch species has its own AI-generated music track — Latin Pop, K-Pop, Afropop, Kawaii, Cinematic, and more. All original and copyright-free.
Species
Each species is based on a real nudibranch — with real biology informing how they act, what they say, and how they grow. Two species are free to start; six more are available as one-time purchases.
Violet body, orange cerata. Fiery and expressive.
Electric blue, orange rhinophores. Bold and inquisitive.
Iridescent stripes with glowing tips. Dreamy and quiet. $2.99
Purple, white, orange, and black bands. Proud and eccentric. $2.99
Fluffy white with ear-like rhinophores. Playful and warm. $2.99
Pelagic blue and silver wings. Wandering and wild. $4.99
Massive and crimson, a swimmer. Passionate and dramatic. $3.99
Black body, emerald crests. Brooding and deeply loyal. $2.99
Evolution
Your nudii grows and changes over time. The Mythic stage cannot be purchased — it must be earned through a year of care and conversation.
3 days
7 days · baby talk
~60 days · curious
~90 days · full bloom
~120 days · earned only
One final farewell
Environments
Give your nudii a home that suits them. Each environment has its own mood and atmosphere.
+ Hydrothermal Vent, Tide Pool, and Shipwreck available in-app.
Pricing
No ads. No attention tricks. No dark patterns. Just a companion app with an honest price.
Starter
Everything you need to hatch, raise, and love a nudii — with no time limit.
Subscription
For those who want their nudii to remember everything, live longer, and sound extraordinary.
Also: $24.99/year — save 47%
One-time
Optional extras — none required to enjoy a full Nudii life.
Privacy Policy
Last updated: April 2026
Nudii is designed from the ground up to be private. The AI model runs entirely on your device. Your conversations, memories, and pet data are stored locally using Apple's SwiftData framework and are never transmitted to any server.
Nudii stores the following data locally on your device only. None of this is sent to us or any third party:
All purchases are processed by Apple via StoreKit 2. We do not receive, process, or store any payment information. Apple's privacy policy governs all transactions.
Nudii contains no analytics SDKs, no advertising SDKs, and no third-party tracking of any kind. There are no ads in the app.
Nudii is intended for users aged 13 and over. As the app collects no data whatsoever — all conversations, memories, and pet data stay on your device — there is no mechanism by which we could collect or access information from any user, including minors.
All data is stored on your device. To delete all Nudii data, uninstall the app. Everything goes with it — there is no server-side copy.
We will update this page if our privacy practices change. Continued use of the app after any update constitutes acceptance of the revised policy.
Questions about privacy? Email privacy@nudii.app.
Support
Nudii is an independent app. We read every support email and aim to reply within 48 hours.
For bug reports, questions, or anything else — email us directly. Include your iOS version and device model if you're reporting a bug.
support@nudii.app →Questions about how the app handles your data, HealthKit integration, or anything related to privacy.
privacy@nudii.app →All purchases are processed by Apple. For billing issues or refund requests, visit Apple's support page or manage subscriptions in Settings.
Apple Support →Why is the app 2.5 GB? The AI model lives entirely on your phone — that's what makes it private. It needs space to be smart.
Can I recover a departed nudii? Yes, with Deep Diver Premium you can revive a departed nudii.
