The flagship device - the Lumia 920 - features wireless charging and a "PureView" camera which the mobile firm said offered better video and still images than rival smartphones.
Most teenagers will find any reason under the sun not to do their homework. But 16-year-old South Londoner Nick D'Aloisio's excuse is better than most - he has been busy developing an app which has made international headlines and attracted a big investment from a Hong Kong-based billionaire.