The smartphone market is slowing, users are holding onto their devices for longer and some manufacturers are feeling the heat. The response from technology firms? Pack the next generation of handsets with crazy features.

Folding screens and an increased number of cameras are among some of the technologies touted to be part of upcoming devices from major firms this year and next.

China's Huawei, which is now the second-biggest smartphone maker in the world, will unveil a folding phone next year. Richard Yu, the CEO of Huawei's consumer division, announced the plans in an interview with German newspaper Die Welt earlier this week.

"Why are you still using a computer? Probably because the smartphone display is too small for you. We will change that. It is conceivable that a display can be folded out," Yu said, according to a translation.

Many companies are thinking about what then next generation of smartphones will look like. While Huawei has managed to grow rapidly, recently overtaking Apple as the world's second-largest smartphone maker, not all vendors have fared well. Smartphone shipments fell 1.8 percent year-on-year in the second quarter, according to IDC (International Data Corporation), with Samsung seeing a decline of over 10 percent.

The South Korean electronics giant is looking towards boosted features to help reverse that. In an exclusive interview with CNBC, DJ Koh, the CEO of Samsung's mobile division, said his company would unveil details of a foldable smartphone this year.

While many may perceive foldable phones to be a variant of a flip phone, the technology is very different. Flip phones relied on a hinge to connect two separate parts of the device. Foldable phones will actually see screens that are able to bend thanks to advances in display technology. The idea, as Yu said, is to increase the screen size of a device, but still allow a user to keep it in their pocket.