Goniometer: Range of Motion

Measure joint range of motion with the device already in your pocket. Goniometer turns the iPhone's motion sensor into a clinical-style goniometer: place the phone against the limb, read the live angle, and lock it when steady.

Built for occupational and physical therapists, hand therapists (CHTs), chiropractors, physicians, nurses, athletic trainers, ATPs, and students — and used by patients tracking recovery at home. Reviewed against standard supine technique. Smartphone inclinometer measurement has been shown valid and reliable (Keogh et al., systematic review, PLOS ONE, 2019).

Measuring is free and unlimited: all 55 movements, every joint from the neck to the fingertips, plus Quick Angle and a built-in Level. No measurement caps, no ads, no account, and no trial needed to measure. The free tier also includes your first patient profile, unlimited PDF and CSV export (watermarked, never capped), and a Face ID lock. Pro is a one-time purchase, never a subscription.

MEASURE IN SECONDS
• Live, gravity-referenced angle, large and readable
• Flat and upright starts read 0° automatically — no calibration, with a Set Zero override for patients who can't reach the standard position
• Stability indicator: lock only when steady
• Optional spoken angle, so both hands stay free

ANIMATED PLACEMENT GUIDES
Every movement has a step-by-step animated guide with an anatomical diagram: patient position, where the iPhone lies, and the motion from start to end range.

55 MOVEMENTS — NECK, UPPER AND LOWER EXTREMITY, AND EVERY FINGER
Cervical spine flexion, extension, lateral flexion, and rotation · shoulder flexion, extension, abduction, and internal/external rotation · elbow flexion and extension · forearm pronation and supination · wrist flexion, extension, and radial/ulnar deviation · hip flexion, extension, abduction, adduction, and internal/external rotation · knee flexion and extension · ankle dorsiflexion and plantarflexion.

HAND & FINGER ROM
Measure every finger and thumb joint — MCP, PIP, and DIP (and thumb MCP/IP), flexion and extension — with a guided two-placement technique. Patient Profiles compute Total Active Motion (TAM) per digit automatically — a standout for hand therapists (CHTs).

QUICK ANGLE & LEVEL — MEASURE ANY ANGLE
Measure any angle with Quick Angle — wheelchairs, splints, ramps, and seating — and check that footplates and trays sit even with the built-in Level.

NORMAL ROM REFERENCE
A searchable reference of normal range values, linked to each placement guide.

PATIENT PROFILES — YOUR FIRST ONE IS FREE
Create a profile with a de-identified label, a movement checklist, and left/right sides, then record a reading for each movement. Tag readings active or passive (AROM/PROM) and add, correct, or backdate any reading. A deletable example patient shows trend charts, summaries, and reports.

PRIVATE BY DESIGN — NO DATA COLLECTED
Fully offline: no accounts, no servers, no analytics, no tracking — the App Store privacy label reads "Data Not Co