The iPhone has a built-in Compass app, but it's basic — it shows heading and that's about it. No True North toggle, no interference detection, no µT sensor readout, no bearing lock, and no way to know if a nearby magnet is making your reading unreliable.
For casual use, the built-in app works. But for hiking, navigation, or any situation where accuracy matters, a dedicated compass app with calibration and diagnostics is worth installing.
Download: NorthPin for iPhone
NorthPin covers every item on that list. The True North mode automatically corrects for magnetic declination at your location using your GPS — so the compass points to true geographic north, not magnetic north that drifts based on your location on Earth.
Most compass apps tell you to do a figure-eight to calibrate, but don't explain why or show you how well it worked. NorthPin guides you through the figure-eight motion and confirms calibration quality. If you're near a source of interference (a speaker, a metal bracket, a car door), the interference detector flags it before you rely on a bad reading.
The Pin Direction feature locks your current heading. Set a bearing to your destination, lock it, and navigate by keeping the arrow pointing toward the pin. This is the feature serious hikers use for off-trail navigation when GPS maps aren't available.
The microtesla meter shows raw magnetic field strength. This is how you identify interference — typical outdoor Earth field is 25–65 µT. If you're seeing 200 µT indoors, something metallic is distorting the reading. NorthPin shows this in real time so you can move away from the interference source.
The built-in Compass app shows heading, True North (when location is on), and that's essentially it. NorthPin adds interference detection, Pin Direction bearing lock, µT readout, calibration guidance, and a shareable diagnostic report — without any ads or account requirements.
Most third-party compass apps on the App Store fall into two categories: ones that are essentially reskins of the stock compass, and ones that add features but bury them behind ads or in-app purchases. NorthPin is free and ad-free for all features.
A compass app (and NorthPin specifically) excels when you need heading without active GPS routing — saving battery life on long hikes, checking orientation in a tunnel or basement, or navigating by traditional landmark-bearing techniques. It works entirely offline. For turn-by-turn directions, use a GPS app alongside.
Get NorthPin True North Compass on the App Store — free, no ads, no account, works completely offline. The most complete iOS compass app available at no cost.
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