Geolocation uses the location feature on your mobile device to work out whether you are at home and then turns the heating on / off accordingly.
When you set up Geolocation you will set a “home boundary” and an “away boundary”, these can be the same or different distances. When the mobile device crosses the away boundary the heating will switch off, when it comes back across the home boundary heading towards home, then the heating will come back on.
All householders can be set up with Geolocation. When more than one mobile device is set up then the heating will turn off when the last person leaves and turn on when the first person comes back.