DA VINCI'S CODEX

The geometry
of a perfect spine.

CheckNeck uses your AirPods' built-in motion sensors to track your head position in real-time. No camera. No wearable. Just put on your AirPods and let Da Vinci's geometry fix your posture.

Download Free Try Live Monitor
CheckNeck
POSTURE INTELLIGENCE
4.9 App Store Rating
50K+ Active Users
87% Posture Improved
LIVE DEMO

Try it right now.

Experience CheckNeck's posture monitoring directly in your browser. Tilt your device or move your mouse to see real-time feedback.

-- Initializing...
PITCH 0.0°
ROLL 0.0°
YAW 0.0°
Posture
Stability
Alignment
Click Start to begin real-time posture tracking
CODEX VISUAL LANGUAGE

Built on the Golden Ratio.

Every pixel follows phi = 1.618 — the same divine proportion Da Vinci used to map the perfect human body.

Golden Spiral

The logarithmic spiral derived from phi governs every curve and animation in CheckNeck's interface.

Vitruvian Spine Mark

72-tick compass bezel, C1-C7 vertebrae column, and Da Vinci's golden spiral — our anatomical brand mark.

Hexagonal Phi-Rings

Three nested hexagonal progress rings track posture, squats, and neck exercises with neon glow feedback.

CODEX FEATURES

Engineered like a masterwork.

Every feature crafted with the precision of a Renaissance workshop.

AirPods Head Tracking

Uses Apple's CMHeadphoneMotionManager to detect your head pitch, roll, and yaw with sub-degree precision. Works with AirPods Pro, 3rd gen+, and Max.

100Hz SAMPLING

Real-Time Score

Live 0-100 posture score with dynamic hexagonal rings and haptic alerts when posture dips.

HEXAGONAL UI

Smart Protocols

5 adaptive daily schedules from Sedentary to Athlete with intelligent exercise timing.

AI SCHEDULING

Guided Exercises

Squats, neck rotations, and walking with real-time form detection via head motion.

MOTION TRACKED

Background Monitoring

Continuous posture tracking even when CheckNeck is in the background. Get gentle nudges when you slouch — without ever opening the app.

ALWAYS ON
THE METHOD

Three steps to perfect posture.

01

Connect AirPods

Just wear your AirPods. CheckNeck instantly connects to Apple's head motion sensors — no pairing, no setup.

02

Calibrate in 3 Seconds

Sit up straight for 3 seconds. CheckNeck captures your ideal posture as a personal baseline.

03

Get Real-Time Coaching

A live posture score, gentle haptic nudges, and smart exercise prompts keep your spine aligned all day.

INSIDE THE APP

See it in action.

Real screenshots from CheckNeck. Every interface element follows the Golden Ratio.

CheckNeck Home — Posture Radar at 100% Excellent

Posture Dashboard

Live hexagonal radar showing your real-time posture score, achievements ring, and hydration tracking.

CheckNeck Smart Schedule — Protocol Selection

Smart Schedule

Five adaptive protocols from Sedentary to Athlete. AI-timed exercise blocks throughout your day.

CheckNeck Squats — Hexagonal Reactor Core Tracking

Exercise Tracking

Hexagonal reactor-core UI tracks squat depth via head motion. Real-time rep counting and form scoring.

THE SCIENCE

Precision meets anatomy.

Apple's CMHeadphoneMotionManager provides medical-grade head tracking data at 100Hz.

Pitch

Forward/backward head tilt. The primary indicator of slouching — detected with 0.1 degree precision.

score = max(0, 100 - |pitch delta| * 4)

Roll

Ear-to-shoulder tilt. Catches lateral imbalances that lead to muscle tension and headaches.

threshold: 10deg good / 15deg fair

Yaw

Left/right rotation. Tracks neck twist exercises and detects asymmetric posture habits.

drift-free via rotation rate
GUIDED EXERCISES

Move with precision.

Three motion-tracked exercises with real-time form detection through your AirPods.

Squats

World-vertical acceleration tracking detects squat depth independent of head orientation. Real-time form scoring.

DEPTH: 0-8 scale DETECTION: acceleration

Neck Rotations

Yaw angular velocity integration tracks full left-right rotation range. Drift-free rep counting.

RANGE: +/- 70 degrees DETECTION: yaw rate

Posture Walking

Pedometer + gait filter relaxes thresholds during walking while still tracking upper body alignment.

CADENCE: 50+ steps/min DETECTION: pedometer
INVESTMENT

Choose your Codex.

FREE
$0
  • 3 posture checks per day
  • 5-minute monitoring sessions
  • Basic posture score
  • 1 exercise type
Get Started
MOST POPULAR
PREMIUM
$4.99/month
  • Unlimited monitoring
  • Background tracking
  • All 3 exercise types
  • Smart protocols
  • Full posture history
  • Custom alert timing
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ANNUAL
$29.99/year
SAVE 50%
  • Everything in Premium
  • Priority support
  • Early access to features
  • 6 months free
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"Simplicity is the ultimate sophistication."
— Leonardo da Vinci

Begin your Codex journey.

Download CheckNeck free today. Your spine will thank you.

Download on the App Store

Requires iPhone with iOS 17+ and AirPods Pro / 3rd gen+ / Max

100% Privacy No Camera Low Battery