From Black Cat Systems:
If you're a pilot, you often need to make lots of weather related calculations. Now there's an easy solution, as close as your iPhone. Weather Calc performs the following weather relation calculations: Altimeter Setting - compute the altimeter setting based on elevation and station pressure. Cricket Temperature - just for fun. This lets you estimate the temperature based on the chirp rate of a cricket. Heat Index - compute the heat index based on the temperature and relative humidity. Pressure - convert between hPa, atmospheres, psi, and inches and mm of mercury (Hg). Relative Humidity - compute the wet bulb and dewpoint based on the temperature, pressure, and relative humidity. Speed Of Sound - displays the speed of sound in various units, given the temperature. Standard Atmosphere - compute the temperature, pressure, density, viscosity, speed of sound, and more. Station Pressure - compute the station pressure based on the elevation and altimeter setting. Temperature - convert between degrees Fahrenheit, Celsius, Kelvin, and Rankine. Virtual Temperature - compute the virtual temperature based on the temperature, dewpoint, and pressure. Vapor Pressure - com[ute the saturated and actual vapor pressure, as well as relative humidity. Wet Bulb - compute the dewpoint and relative humidity based on the temperature, pressure, and wet bulb reading. Wind Chill - compute the wind chill based on the temperature and wind speed. Wind Speed - convert between knots, kilometers/hour, meters/second, miles/hour, feet/second. Buy your copy now, and let Weather Calc take the drugery out of weather related calculations.