LONDON - Trials of a Harry Potter-inspired tracking device which can monitor movements of family members through their mobile phones have been completed.

Microsoft’s Whereabouts Clock features a screen which has the ability to show the approximate location of an individual - such as “school”, “work” or “gym”.

The revolutionary device works by identifying which cell of a mobile phone network a family member is in at any given time. When users set up the Whereabouts Clock they have to give each cell a name, such as “work” or “school”, by downloading software onto their phone. The device recognises their location each time they enter that cell.

Users who don’t want others to know their location can switch off the application, reports The Times.

The system was installed in the homes of several families living near the company’s research laboratories in Cambridge.

The company is now looking at how to market the product.

Richard Harper, who heads Microsoft’s socio-digital systems research group, said: “We want it to give enough information to be comforting without giving so much that people feel they are being watched.”

The system is reminiscent of a device in Rowling’s novels.

The parents of Ron Weasley, Harry’s friend, own a magic clock with a hand representing each family member. The hands point to locations on a dial including “home”, “work” and “mortal peril”. (ANI)