A fully functioning aviation altimeter for the Apple Watch Series three or later.  Hop to the App Store!

Just like its big brother App for the iPhone and iPad, Aviation Altimeter for Watch is the only watch-based altimeter which has the Kollsman adjustment so you can adjust the altimeter to the current barometer setting, or to 29.92 inches of mercury for the pressure altitude.

Aviation Altimeter for Watch displays altitude in feet, meters, or Flight Level.  It can also show you the raw ambient pressure in millibars.  Field Setting can be in inHg or millibar units.

    

There is also a haptic reminder for Oxygen when you exceed 12,500 feet.

To change your preferences, you can either swipe left on the Watch face, or use the accompanying iPhone App.

Need a quick backup for your panel? Aviation Altimeter for Watch uses the latest Apple and Bosch technology built into the Apple Watch Series 3 and later models.