Barograph displays the air pressure in millibar or inHg of the last 24 hours in a graph. You can enable a storm alarm, show the history of the past week and correct the pressure to sea level with a fixed altitude or using the altitude from the GPS. Works only on android devices that have a barometric sensor, like the Motorola Xoom, Galaxy Nexus, Galaxy Note or the Sony Xperia Active (Please let me know if there are other devices that have a barometric sensor).