Aviation Altimeter for Watch, developed by Aviametrix LLC, is a comprehensive aviation altimeter exclusively designed for Apple Watch Series 3 and higher. This altimeter operates independently, allowing users to set field altimeter settings, display altitude in Feet, Meters, or Flight Level, and show raw barometric pressure. The app features a Kollsman window for adjusting local pressure in inches of mercury or hectoPascals. Users can customize preferences directly on the watch by swiping left, ensuring functionality without a phone nearby or internet connection.

Swipe right to view current density altitude by using the watch crown to set the ambient temperature. The AltAlert feature enables users to set a target altitude and range, providing graphical alerts when exceeded. Additionally, an oxygen alarm reminds users visually and haptically when surpassing 12,500 ft, but note that the app is not FAA TSO-certified for primary flight use.