This application gives BT home broadband customers easy mobile access to free and unlimited wi-fi and includes a mapping service which is updated weekly so that customers can find their nearest hotspot. Once BT home broadband customers have downloaded the app, all they need to do is input their btinternet email username and password, and open the app whenever they are in a BT wi-fi area. Because access is unlimited and free for BT home broadband customers it will help customers prevent racking up extra data costs.     BT’s wi-fi network is the biggest in the UK – made up of BT Openzone and BT FON hotspots – and…