This apps is for leisure and educational only.
Taken barometer pressure reading, optionally adjust the barometer pressure reading to your references.
The adjusted air pressure is to calculate the altitude by basing on the manually entered QNH airport Mean Sea Level Pressure.
For best result, choose the nearest QNH / weather station mean sea level pressure report.
Most users will be below transition altitude so the QNH should be used.
Air pressure / barometric reading changes during the day, it is best to reference the QNH and / or weather station before using this apps.
Mean Sea Level Pressure range between 1090 hPa and 850 hPa
Measured Adjustment range between +/- 1000 Pa
Calculation is based on 15C 59F.
GPS reception requires clear sky view and Sense is slow on acquiring GPS and may takes sometime. It is nothing the apps could speedup.