Mobile phone anniversary: The next 40 years

It has now been 40 years since the first mobile phone call when Motorola engineer Martin Cooper rang a technology rival from a "cell" phone in New York.

The device was almost 23cm tall and weighed more than one kilogram. It contained 30 circuit boards, had a talk-time of 35 minutes and took 10 hours to recharge.

Now modern mobile phones let us send emails, take photos, listen to music and watch videos. So what does the future hold for mobile phones?

The BBC's Tim Willcox spoke to Amy O'Donnell from FrontlineSMS and Ben Medlock, founder of mobile app SwiftKey.