DuoCorder+ Downloads & RevenueDuoCorder+ · App Store

DuoCorder turns your iPhone into a handheld sensor scanner. See what your phone can sense about the world around you, live, on one retro-futuristic display.

ONE-TAP FULL SCAN
Press SCAN and DuoCorder samples every sensor for ten seconds, then explains what it found in plain language: "No magnetic anomalies", "Air pressure falling", "Conversation-level sound". Save the report or share it.

MORE THAN A DOZEN LIVE INSTRUMENTS
• Motion: acceleration, rotation, tilt and a bubble level
• Compass: true and magnetic heading, 3-axis magnetic field strength
• Air pressure: barometer, sea-level pressure, altitude change, pressure trend (iPhones with a barometer)
• Light: ambient light level estimated from the camera's exposure
• Sound: level in decibels, a live spectrum, and a scrolling spectrogram
• Pitch: names the strongest note you hear, with how sharp or flat it is
• Position: coordinates, speed, course, accuracy and the nearest place name
• Activity: steps, distance, floors climbed, cadence and pace
• Bluetooth radar: nearby devices, signal strength and a rough range estimate
• Your phone: battery, CPU, memory, storage, temperature and network

METAL DETECTOR MODE
Sweep the phone slowly and listen. The tone rises in pitch and the haptic ticks speed up as the magnetic field changes near metal.

YOUR OWN ALERTS
Create rules such as "pressure falling faster than 2 hPa/hour", "magnetic field above 70 µT" or "battery below 20%". DuoCorder chirps, buzzes and flashes the screen when one triggers, and keeps a history of recent alerts. Alerts work while the app is open.

24-HOUR TRENDS
DuoCorder records your readings while it is open and keeps the last 24 hours. Chart any sensor over 5 minutes to a full day, drag to inspect values, and see your alert thresholds on the chart.

SNAPSHOTS AND SHARING
Save a snapshot of any page, with your location, then browse your log or export everything as a CSV file. Share a full readable report in one tap.

EASY TO LEARN
Tap any reading to see what it means, view its trend or set an alert. A quick guide explains the controls, and every button is clearly labelled.

BUILT FOR BIG AND FOLDABLE SCREENS
The layout fills iPhone, iPad and wide two-panel displays, with the display on top and the keys below.

PRIVATE BY DESIGN
Everything stays on your device. There are no accounts, no ads, no analytics and no tracking. The microphone, camera and Bluetooth run only while the page or scan that needs them is open. Sound is analysed live and never recorded. The camera is used only for its light reading, and no photos or video are saved.

GOOD TO KNOW
Readings come from your phone's built-in sensors and are approximate. Which sensors you see depends on your device; for example, the barometer is not in every iPhone. DuoCorder is for curiosity and learning, not for medical, safety, navigation or professional use.