Israeli developers have created a digital pen that allows its users to write on a smartphone using any surface.

With a Bluetooth connection, Phree turns a sofa, a hand or someone else's face into a writing surface - and instantly transfers the text to a phone.

A campaign on crowdfunding site Kickstarter saw the invention achieve its goal of £64,000 in just a week, with more than £240,000 now donated by 2,000 backers.

Gilad Lederer, who created Phree with brothers Opher and Uri Kinrot after three decades of working together, said that although the device had many potential uses, their main aim was to make digital communication more personal. "It's easy and natural. It's the human way," he added.

Companies have been vying to make phone messaging more human for years, with animated icons called emojis and video messaging, but Mr Lederer argued this method was more intuitive. "Emojis are natural, but what could be more natural than writing and annotating in your own handwriting?"