Your AI companion lives on your phone, not in the cloud.
Nudii is a virtual nudibranch sea slug powered by AI that runs entirely on your iPhone. No chat servers. No subscription to start. Your conversations stay on your device.
Be the first to know when Nudii launches.
Waitlist emails are handled by Formspree for this website. The Nudii app itself keeps your conversations on your device.
🔒 Your conversations never leave your phone.
Nudii runs Gemma on your iPhone for chats. No Nudii chat servers. No account required. What you share with your nudii stays with your nudii.
How It Works
Private by design. Emotional by design too.
We keep the public story focused on what matters to players: the relationship, the privacy model, and the shape of the experience.
Hatch a real nudibranch species
Start with one of two free species, tap your egg to hatch the moment you are ready, and name a companion that feels personal from day one.
Talk, care, and build memory
Conversations, care rituals, mini-games, and optional HealthKit activity all shape how your nudii responds and what it remembers.
Grow early, then deepen the bond
Your nudii evolves from Egg to Veliger, Juvenile, Adult, Mythic, and eventually Departed. Visible changes start fast; Mythic is still earned, never purchased.
Keep everything on your iPhone
The app is built around on-device AI and local storage, which is why it needs newer hardware and a larger download than a typical pet app.
Features
A companion that actually remembers you.
Built on real marine biology and real on-device AI — not a chatbot with a cute skin.
On-Device AI
Powered by Google's Gemma model running on your iPhone 15 Pro or later. Core chats stay on-device instead of being routed through Nudii servers.
Long-Term Memory
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.
Genuine Evolution
Six phases with a friendlier arc — a short first-hour Egg, then Veliger, Juvenile, Adult, Mythic, and Departed. Each phase changes the relationship. Mythic must be earned; it can't be bought.
Rare Mood Days
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.
Interactive Care
Feed it, clean it, put it to sleep, and play six retro mini-games with it. Real-world steps and workouts via HealthKit earn your nudii bonuses.
Species-Specific Music
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
8 real nudibranchs. 8 unique personalities.
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. Hover to preview the earned Mythic form.
Spanish Shawl
Violet body, orange cerata. Fiery and expressive.
Anna's Chromodoris
Electric blue, orange rhinophores. Bold and inquisitive.
Opalescent
Iridescent stripes with glowing tips. Dreamy and quiet. $1.99
Four-Color
Purple, white, orange, and black bands. Proud and eccentric. $1.99
Sea Bunny
Fluffy white with ear-like rhinophores. Playful and warm. $2.99
Blue Dragon
Pelagic blue and silver wings. Wandering and wild. $4.99
Spanish Dancer
Massive and crimson, a swimmer. Passionate and dramatic. $3.99
Black Nembrotha
Black body, emerald crests. Brooding and deeply loyal. $2.99
Evolution
Fast first growth. Long-term bond.
Your nudii shows visible change early, then settles into a deeper long-term relationship. Mythic still cannot be purchased — it has to be earned.
Egg
~1 hour
Veliger
Day 1-7 · baby talk
Juvenile
Day 7-30 · curious
Adult
Day 30-75 · full bloom
Mythic ✦
Day 75+ · earned only
Departed
One final farewell
Environments
Seven aquariums. One comes free.
Give your nudii a home that suits them. Each environment has its own mood and atmosphere.
+ Tide Pool ($1.99), Hydrothermal Vent ($2.99), and Shipwreck ($2.99) available in-app.
Pricing
Free to start. Deeper if you want it.
No ads. No attention tricks. No dark patterns. Just a companion app with an honest price.
Starter
Free
Everything you need to hatch, raise, and love a nudii — with no time limit.
- Full lifecycle (Egg → Mythic → Departed)
- Unlimited AI conversations
- Up to 50 long-term memories
- 2 starter species (Spanish Shawl & Anna's Chromodoris)
- All care mechanics and mini-games
- HealthKit integration
Subscription
Deep Diver
For those who want their nudii to remember everything, live longer, and sound extraordinary.
- Sea Bunny species unlocked while subscribed
- Coral Reef habitat unlocked while subscribed
- Unlimited long-term memories
- Ongoing revival access for departed nudii
- Mythic stage extension
- All music tracks and premium neural voice
Also: $24.99/year — save 47%
One-time
Add-ons
Optional extras — none required to enjoy a full Nudii life.
- Premium species: Opalescent, Four-Color, Sea Bunny, Blue Dragon, Spanish Dancer, Black Nembrotha
- Aquarium environments: Coral Reef, Deep Sea, Kelp Forest, Tide Pool, Hydrothermal Vent, Shipwreck
- Decorations and special foods
- Single Revive on the death screen
- Stage Boost (Mythic excluded)
FAQ
A few honest answers up front.
The product is unusual, so the website should answer the unusual questions directly.
Why does Nudii need an iPhone 15 Pro or later?
Why is the app around 3 GB?
Is everything completely offline?
Can I get a departed nudii back?
Can I restore purchases after reinstalling the app?
Support
Need help? We've got you.
Nudii is an independent app. We read every support email and aim to reply within 48 hours.
📧 Email Support
For bug reports, questions, or anything else — email us directly. Include your iOS version and device model if you're reporting a bug.
[email protected] →🔒 Privacy Questions
Questions about how the app handles your data, HealthKit integration, or anything related to privacy.
[email protected] →💳 Purchases & Billing
All purchases are processed by Apple. For billing issues or refund requests, visit Apple's support page or manage subscriptions in Settings.
Apple Support →❓ Quick Answers
Why is the app around 3 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. Legacy Rebirth is free, Single Revive is a one-time rescue, and Deep Diver includes ongoing revival access.