During the COVID-19 pandemic and subsequent lockdown, both schools and universities faced significant challenges in moving teaching from an in-situ setting to a remote one, this included laboratory experiments. This paper presents an experiment developed to use a phone's in built pressure sensor, common to most smart phones. By using this sensor to measure the pressure at a series of known heights, the density of air was calculated with an accuracy of approximately ±0.03 kg m[superscript -3]. This was completed as part of a first year undergraduate course.