Samsung has revealed a prototype of its long-awaited foldable smartphone, which allows consumers to own a tablet and a phone in one device.

The brand debuted its vision for the next generation of mobiles at its developer conference in San Francisco yesterday.

According to Samsung, the new foldable model will give users "the best of both worlds", ridding them of the need for multiple devices by combining them into one model.

Users can open Samsung's pocket-sized phone, called Infinity Flex, like a book along its left-hand edge. The unfolded screen is double the size, so the larger display can be used in a similar way to an iPad or tablet.

Could bring "wow factor" back to smartphone market

The brand said the app experience transitions seamlessly from the smaller display to the larger as the device unfolds. Users can also multitask by using three active apps on the larger display.

Tech analysts suggest this development could bring a "wow factor" back to the smartphone market, giving Samsung the edge over Apple, following the long-running patent war between the two companies that saw Samsung accused of copying the iPhone.

The South Korean tech company has urged Android developers to start writing apps for the flexible screen phone, which is expected to hit the market early next year.

At the conference, Justin Denison – who is Samsung Electronics senior vice president of mobile product marketing – showed a prototype with a screen he said measured 18.5 centimetres diagonally, from corner to opposite corner.

When folded in half, the device appeared to resemble a thick phone, however Samsung did not give media or developers the opportunity to look at the device closely.

Android working with Samsung to develop more features

Google's Android software platform is are working with Samsung to develop more features for the phone. According to Dave Burke, vice president of engineering for Android, it is likely that many other manufacturers will release foldable phones next year.

Developer Joshua Clark told Reuters that Samsung would need to sell the technology to its competitors for the product to be widely adopted.

"I really think it only takes two companies, and then all of the sudden it will catch on," said Clark. "And the fact that Google was on stage, that says a lot. For developers to be able to integrate it with all their apps, that gives me a lot of confidence."

"They'll have to prove that it's more than just a gimmick," analyst Bob O'Donnell told the media outlet. "But it's smart to open it up to developers early to do different types of experiences."

Other companies also developing folding phones

Other companies developing foldable phones include China's Huawei Technologies, which has announced plans to launch a 5G smartphone with a foldable screen in mid-2019.

Even further ahead of the game is Chinese mobile display making start-up Royole, which unveiled a foldable Android phone last week boasting a 19-centimetre screen. Called Flexipai, the model is said to become available in late December this year.

Apple was granted a patent for a retro-style flip phone with an OLED screen display back in November 2016 that, like flip phones popularised in the 90s, would be capable of being folded in half across its middle.