Get real-time environmental insights right from your device — no internet required.
Cnav turns your iPhone into a powerful navigation and atmospheric tool. Measure barometric pressure, track elevation, find your heading, and view precise coordinates with a beautifully minimal design that stays readable in any light.
Unlike apps that depend on remote data sources, Cnav reads directly from your device’s sensors to deliver fast, reliable, offline information — perfect for hiking, backcountry trips, sailing, or simply understanding the world around you.
Key Features
• 🌤 Barometric Pressure
• Real-time readings with smooth updates
• Choose your unit: inHg, kPa, or mmHg
• ⛰ Altitude & Elevation
• Accurate elevation above sea level
• View in meters (m) or feet (ft)
• 🧭 Precision Compass
• Minimal, elegant compass design
• Responsive needle animations
• 📍 Coordinates Made Simple
• Clear, customizable coordinate display
• Unit pickers that stay out of your way
• ☀️ Sun Timer (Daylight Awareness)
• At-a-glance information to plan your day outdoors
• 🎨 Beautiful, Adaptive Design
• Dynamic backgrounds: day sky, night sky, steampunk, or automatic
• Subtle materials and shadows for clarity without clutter
• 🔄 Easy Calibration
• One-tap sensor calibration for optimal accuracy
• 🚫 Works Offline
• No Wi‑Fi or cellular required — perfect for remote environments
Why You’ll Love Cnav
A thoughtfully crafted interface that blends elegance with purpose. Semi-transparent materials, refined typography, and fluid motion make every reading easy to read and satisfying to use — whether you’re on a summit ridge or at your desk.
Built for hikers, sailors, weather enthusiasts, and anyone who appreciates precise, on-device environmental data.
Download Cnav and elevate your journey.
Note: Continuous use of GPS and sensor data can decrease battery life. For best results, calibrate your device periodically.
Does this need WiFi or Cellular service/connection?
No. These reading come directly from your iPhone's built-in sensors.
Why does this app go crazy when I'm in the car? The altitude jumped to 6,000 ft!
There are two reasons this may happen.
The electric activity plays havoc with the sensors.
Temperature in the vehicle may effect the internal barometer.
Can I use this with a map for orienteering, hiking, hunting, or exploring?
Yes. This app works well for these activities as there is no need for "signal" and the battery drain is minimal.
Are there plans to have the ability to pin a location and have the compass guide you?
Possibly, if interested is expressed.
I don't like the units the app displays the measurements in.
If there is interest I can add additional units for the pressure, altitude, and compass.
Will there be more options for changing the background color and such?
Based on user input.
Feel free to contact me regarding any questions or suggestions you may have about this app. I am always looking to improve my knowledge and its function.
Email: cardiopulm@me.com
I don't have any setup currently. The app doesn't have any intricate features currently.
This app does not save or log any data from your phone. Additionally it runs locally on your device only. When saving "events" which include (time, date, timezone, heading, elevation, barometric pressure, time until sunset/sunrise, and GPS or other coordinates), these events are saved locally to your phone.
There is no way for me to view your location or other data. Apple frowns upon privacy infringement and so do I.
The sensors/displayed readings will act oddly in a vehicle (car, truck, excavator, UFO, etc).
This app is intended as a supplemental tool and does not replace the need for common sense, proper knowledge, or experience in using a map and/or compass when navigating in the wilderness. Users are strongly advised to plan ahead, carry appropriate gear, and prepare for the conditions of any outdoor activity they undertake.
The developer of this app assumes no responsibility or liability for any decisions, actions, or outcomes resulting from the use of this app or reliance on its readings. Always prioritize safety and sound judgment when engaging in outdoor activities.