The Displacement Estimator uses the iPhones internal sensors to estimate the change in your location. You type in your latitude and longitude, and then begin walking. This app demonstrates that using hardware internal to the iPhone can be an alternative external hardware such as GPS satellites, cell towers, routers, iBeacons, etc. This app assumes a 57cm/step gait and has been measured to introduce 6cm - 15cm of error for every 1m traveled.