1. A machine-implemented method for determining a population density of an area based at least on a geolocation of a user, the method comprising: receiving, by one or more first computing devices, a geolocation shared by a user; determining, by the one or more first computing devices, an area of interest of the user, wherein the area of interest is determined, in part, by the geolocation shared by the user; determining, by the one or more first computing devices, one or more second computing devices in proximity to the determined area of interest of the user based on one or more wireless signals transmitted from the one or more second computing devices; and determining, by the one or more first computing devices, a population density of an area near the determined area of interest of the user based on the determined one or more second computing devices in proximity to the determined area of interest of the user, wherein the population density of the area represents a level of activity by one or more persons.