MyVario

MyVario is a simple-to-use app that displays altitude and vertical speed in a format that all pilots understand.  Human factors was important in the development of this app.
The altitude (above mean sea level) is calculated by using filtered GPS data. The variometer uses the change in altitude over time to calculate vertical speed (in knots).  A Kalman Filter has been tuned and is used to smooth the variometer presentation.  You should find the variometer to be smooth but responsive enough to show small rates of climb or descent.  As with commercial variometers, the user can set the sensitivity.

MyVario also includes a Test mode that shows varying altitude and vertical speed.  This is handy for becoming familiar with the instrumentation or simply demonstrating the app to others.

As with all portable electronic devices, MyVario should never be used as a substitute for approved cockpit instrumentation.  Under rare circumstances, the altitude my be off.  This could be due to poor GPS reception or a failure of the hardware or software.