How do you use GPS to locate someone's cellphone?

Use GPS to locate someone's cell-phone by providing a map location of the lost phone on a screen. You can only obtain GPS map coordinates of a lost phone if the phone includes a GPS tracking device, such as the TrackR.

The TrackR device combines a tracker device with the TrackR app to help locate lost phones or other items through the CrowdGPS system. The TrackR app shows the device location and a distance indicator to determine how far away a lost phone is. TrackR also features a separation alert that notifies users when someone leaves phone behind. Additional features include an item ringer to buzz the lost phone when nearby.