Privacy-First by Design
How Treelet builds local-first health, fitness, and wellness apps — with on-device AI, Apple Silicon acceleration, and zero-cloud storage for your sensitive data.
Why privacy is the product
Health journals, blood pressure trends, mood notes, skin scans, and family check-ins are among the most intimate data people keep on a phone. Most “smart” apps ship that data to remote servers for convenience. Treelet takes the opposite path: we design private iOS apps where computation stays on your device whenever possible.
That choice is not a marketing slogan. It shapes architecture — local databases, Apple HealthKit integration, on-device models, and optional cloud only when you explicitly need sync across your own devices. If you are searching for a local-first health tracker or privacy-focused wellness apps for iPhone, this page explains how our ecosystem works.
Local-first health tracking
A local-first health tracker keeps primary records on the device you control. Treelet Health, Treelet Diary, Treelet TCM, and related apps read and write through Apple Health and on-device storage so trends, journals, and constitution insights remain yours.
- Apple Health as the hub — vitals and activity stay in the system you already trust, instead of a proprietary cloud silo.
- On-device journals — mood and wellness notes in Treelet Diary are processed locally, including on-device AI assistance where available.
- No account required for core use — many Treelet apps are usable without creating a cloud identity just to open a chart.
Looking for free web tools without an account? Try the BMI calculator, blood pressure interpreter, and BMR tools on treelethealth.com — then deepen tracking in the iOS app. BMI →
On-device AI on Apple Silicon
Modern iPhones include a Neural Engine built for private machine learning. Treelet uses on-device AI for features such as tongue and constitution assistance in Treelet TCM, skin analysis in Treelet Beauty, jump-rope counting in Treelet Skip, and local writing help in Treelet Diary — without uploading raw media to our servers by default.
What “on-device” means in practice
- Inference at the edge — models run on Apple Silicon / Neural Engine so photos, audio cues, and text stay on the phone.
- Offline-capable workflows — core analysis continues when you are offline or prefer airplane mode.
- Less attack surface — data that never leaves the device cannot be breached from a remote database we do not operate.
This is how we approach private iOS apps: treat the Neural Engine as the default compute plane, and treat the network as optional.
Zero-cloud store for sensitive wellness data
“Zero-cloud store” means Treelet does not run a mandatory cloud vault for your health history, diary entries, or biometric-derived insights. We avoid building a honeypot of user medical-adjacent data. Where App Store distribution, licensing, or optional sync requires a network call, we keep it minimal and purpose-bound.
- Default: device storage — your records live with you.
- Optional: Apple ecosystem sync — when sync exists, prefer system mechanisms you already manage (e.g. Health, iCloud you control) over a Treelet mega-database.
- Transparent policies — each product publishes its own privacy policy; start from the app pages on treelet.us.
Who this is for
Privacy-first does not mean feature-poor. It means you can track blood pressure trends, walk and run with Treelet Fit, grow a step farm in TreeletMove, check in with family via Still OK, or capture moments with Yun — while keeping the architectural bias toward local computation.
If you care about local-first software, Apple-native design, and health data that does not need to live on someone else’s server, the Treelet ecosystem is built for you.
Explore the ecosystem
Continue to the product hub, open Treelet Health tools, or follow updates on X.