AirCalc

Displays relative wind with a moving arrow.

Displays components for crosswind and head/tail wind.

Pressure altitude, density altitude and true airspeed are calculated from calibrated airspeed, altitude and temperature.

Where available, pressure altitude is derived from the internal barometer.

Wind speed and direction are computed from true airspeed and heading and from internally derived GPS track and groundspeed.

The Options page allows you to select your preferred units.